DE102005043918A1 - Detector arrangement and method for determining spectral components in a radiation incident on a detector arrangement - Google Patents

Abstract

A detector arrangement (10) having a plurality of discrete radiation detectors (1, 2, 3) is proposed, wherein a first radiation detector and a second radiation detector of the detector arrangement each have a semiconductor body (11, 21, 31) with a radiation reception and signal generation active region (12, 22, 32) and in each case one, the respective radiation detector associated detection region, wherein the semiconductor body, in particular the active region, at least one radiation detector contains a III-V semiconductor material and / or wherein the active region of the first Radiation detector is designed differently from the active region of the second radiation detector. Such a detector arrangement is particularly suitable for the detection of radiation in different-colored spectral regions.

Description

The The invention relates to a detector arrangement with a plurality of Radiation detectors and a method for determining spectral Shares of incident on a detector array radiation.

to Radiation detection in different wavelength ranges often becomes a detector array having a plurality of juxtaposed Si photodiode chips used for radiation detection. On the single Si photodiode chips associated external filter becomes the spectral sensitivity distribution of the respective Si photodiode chip adapted to the desired detection range. Such a detector arrangement with a plurality of Si photodiode elements is from the provisional Data sheet for the component "MTCSiCT" from Laser Components known. However, this component is due to the elaborate Dielectric filtering comparatively expensive.

Si photodiode chip continue to show mostly their maximum sensitivity in the infrared Spectral range on. In contrast, in the visible spectral range produce Si photodiode chips usually a comparatively low signal, so that radiation detection by Si photodiode chips in the visible Spectral range opposite Detection in the infrared spectral range is inefficient.

A The object of the present invention is to provide an improved detector arrangement, in particular for the efficient detection of radiation in the visible Spectral range, to be specified. Furthermore, it is an object of the invention a method for determining spectral components in one on one indicate effective radiation detector radiation incident, the the determination of the spectral components by cost manufacturable Radiation detectors allows.

These The object is achieved by a Detector arrangement with the features of claim 1 or by a method with the features of claim 18 solved. advantageous Further developments and embodiments of the invention are the subject the dependent Claims.

A inventive detector arrangement comprises a plurality of, in particular laterally juxtaposed, discrete radiation detectors, wherein a first radiation detector and a second radiation detector of the detector array, respectively a semiconductor body provided with a radiation reception and signal generation active area and one, the respective radiation detector have associated detection area.

Of the Detection range here is preferably one, in particular connected, Wavelength range, in which the respective radiation detector is sensitive, that is, in the from the respective radiation detector a significant, recognizable by a background noise signal is generated.

Conveniently, the detection range is in a wavelength range for which the Detector arrangement or the respective radiation detector for radiation detection is provided. The respective radiation detector can specifically for Detection may be formed in a predetermined detection range.

at of the invention the semiconductor body, in particular the active region, at least one radiation detector, in particular the active region of the first radiation detector and the active region of the second radiation detector, a III-V semiconductor material and / or it is the active area of the first radiation detector different from the active area of the second radiation detector executed.

From a radiation entrance side, which is the semiconductor body of a Radiation detector of the detector arrangement expediently, in the Semiconductor body incoming radiation hits the active area of this radiation detector. contains the incident radiation wavelengths for the the radiation detector is sensitive, then a corresponding proportion of the radiation power in the semiconductor body, especially the active area, the radiation detector absorbs. The electron-hole pairs generated in the sequence in the active region carry to the signal of the radiation detector at.

through a III-V semiconductor material in the signal-generating active region can, in particular in the visible spectral range, an advantageous high internal quantum efficiency in the generation of electron-hole pairs due to photons striking the active area become. A high internal quantum efficiency usually goes with one increased favorably Efficiency of the radiation detector associated.

Through various implementations of the active regions of the first and second radiation detectors, the tuning of the detection regions of the respective radiation detectors for radiation detection in different spectral regions becomes relieved. A discrete and separate, that is not monolithically integrated, embodiment of the radiation detectors of the detector arrangement, the production cost can be reduced with advantage. Due to the separate embodiment, individual radiation detectors of the detector arrangement, in particular their semiconductor body, can be manufactured in a coordinated manner to a predetermined detection area assigned to the respective radiation detector.

In a preferred embodiment is a band gap and / or a thickness of a Functional layer of the active region of the first radiation detector from a band gap or a thickness of a functional layer of the active region of the different radiation detector. The formation of a detector arrangement with radiation detectors for different Detection areas can be facilitated.

About the bandgap the functional layer, the detection range can be influenced or molded. The functional layer preferably absorbs in Substantial radiation in a wavelength range, the wavelengths smaller the band gap the functional layer corresponding wavelength.

The Thickness of the functional layer determines that in the functional layer absorbed portion of radiation power from the on the detector array incident radiation. About here can the strength the detector signal, such as the photocurrent or derived therefrom Sizes, of each radiation detector can be set specifically. A increase The thickness of the functional layer usually results in a increase which in this absorbed radiation power, which in turn in the Usually higher Signals.

In In another preferred embodiment, the band gap of the Functional layer of the active region of the first radiation detector corresponding wavelength and / or the band gap of the Functional layer of the active region of the second radiation detector corresponding wavelength in the visible spectral range. The formation of a detector arrangement for the efficient detection of radiation or for the determination of a spectral component in the visible spectral range is facilitated in the sequence.

It It should be noted that here as a visible spectral range that Wavelength range, in which, especially light-adapted or dark-adapted, human Eye, according to the CIE eye sensitivity curve (CIE: Commission Internationale de l'Eclairage) is sensitive becomes. In doubt, the wavelength range between 420 inclusive nm and inclusive 700 nm as a visible spectral range, especially for the light-adapted human eye, to be viewed.

In In another preferred embodiment, the band gap of the Functional layer of the active region of the first radiation detector corresponding wavelength and the band gap the functional layer of the active region of the second radiation detector corresponding wavelength in different colored spectral ranges. The detection or the Determination of different colored spectral components in one on the Detector radiation is thus facilitated. The Detector arrangement can in particular for the detection of different colored spectral components, such as fractions of the primary colors red, green and blue, be provided or trained.

In In another preferred embodiment, the detection area overlaps of the first radiation detector and the detection area of the second Radiation detector, in particular only partially or completely. The Detection of radiation via a coherent one Wavelength range, about the visible spectral range is thus facilitated. With preference is the detector array over a coherent, in particular predetermined, detection wavelength range, e.g. over the visible Spectral range, sensitive. The detection wavelength range can by means of overlapping Detection areas of the individual radiation detectors may be formed.

In In another preferred embodiment, the first and / or the second radiation detector is a respective radiation detector associated, given spectral sensitivity distribution with one, local or global, maximum at a given maximum wavelength.

For the spectral Sensitivity distribution of a radiation detector is here the dependence of the signal generated in the active region of this radiation detector (e.g., the photocurrent or quantities derived therefrom) from the wavelength of the radiation detector incident radiation prevail.

Prefers is the maximum wavelength and / or the band gap the functional layer of the active region of the radiation detector corresponding wavelength in the detection area associated with this radiation detector.

The generation of a comparatively high detector signal in the detection range of the radiation detector can thus be achieved in a simplified manner. In particular, this is to be seen in contrast to comparatively inefficient detectors whose Band gap or maximum sensitivity is outside the detection range, as is often the case for example in detection in the visible spectral range with conventional Si photodiode chips.

In a further preferred embodiment of the detector arrangement has at least one radiation detector, in particular a plurality of radiation detectors, the detector assembly has a filter layer structure with at least a filter layer. The filter layer structure is preferred in the semiconductor body the radiation detector monolithically integrated. In the filter layer structure can out the incident radiation components are absorbed, not for signal generation in the active area of the radiation detector reach. Conveniently, is the filter layer structure between a radiation entrance side the radiation detector, in particular a radiation entrance side of the semiconductor body this radiation detector, and arranged the active region of the semiconductor body and / or trained. The filter layer structures of radiation detectors for different Detection areas are further expediently different from each other executed.

Further The filter layer structure preferably absorbs radiation in one Wavelength range, the wavelength smaller than the maximum wavelength of the Spectral sensitivity distribution of the radiation detector and / or wavelength smaller than the band gap the functional layer of the active region of the radiation detector corresponding wavelength having.

through The filter layer structure can be the spectral sensitivity distribution the radiation detector or the detection area of the radiation detector, especially on the shortwave side for wavelengths smaller than the maximum wavelength and / or the band gap the functional layer of the radiation detector corresponding wavelength, targeted be formed. The filter layer structure can be a short-wave Cutoff wavelength the spectral sensitivity distribution of the radiation detector and / or a short-wave cut-off wavelength of the detection area determine the radiation detector. In the filter layer structure absorbed radiation does not reach the active area, so that in the absorption wavelength range the filter layer structure only a correspondingly reduced signal is produced. A band gap The filter layer determines the absorption wavelength range the filter layer and a thickness of the filter layer the proportion of from the incident radiation absorbed radiation power.

In In an advantageous development, two radiation detectors the detector assembly formed such that a composition a filter layer of the filter layer structure of the one radiation detector equal to the composition of the functional layer of the active region the other radiation detector of the detector array is. The other Radiation detector here preferably has a detection area on, the wavelengths smaller than the band gap of the wavelength corresponding to a radiation detector. The tuning of the detection areas of the two radiation detectors the detector assembly to each other, such that a comparatively low overlap their detection areas and / or their sensitivity distributions results can be so relieved. Particularly preferred the filter layer of the one radiation detector has a thickness, equal to the thickness of the functional layer of the other radiation detector is. The formation of the individual radiation detectors for the detector arrangement and their coordination with each other can be further facilitated become.

In a further preferred embodiment, the filter layer structure a plurality of filter layers. The filter layers of the filter layer structure can for example, for the absorption of radiation with wavelengths different wavelength ranges be formed so that the targeted shaping of the spectral sensitivity distribution a radiation detector, in particular for wavelength smaller than the maximum wavelength, simplified can be done. The filter layers preferably have the filter layer structure this different band gaps and / or thicknesses up. The absorption wavelength region of the filter layer structure can face this way a structure with a single filter layer with advantage targeted be influenced or broadened.

In In another preferred embodiment, there are two radiation detectors the detector arrangement is formed such that the detection range of the a radiation detector that the band gap of the functional layer of the other radiation detector corresponding wavelength includes.

The detection range of the other radiation detector preferably has wavelengths outside the detection range of the one radiation detector. Preferably, the other radiation detector is provided as compared to the one longer wavelength radiation detector. The other radiation detector thus generates signals both in the detection area assigned to it and in the detection area of the one radiation detector. Although the determination of spectral components is thus made more difficult, the radiation detectors can advantageously be manufactured at lower cost. In particular, it is possible to dispense with a filter layer structure. Optionally, the maximum waves Length of the other radiation detector are within the detection range of a radiation detector.

In In another preferred embodiment, there are two radiation detectors the detector arrangement is formed such that the band gap of the functional layer the wavelength corresponding to a radiation detector outside the detection range of the other radiation detector is located.

This can be achieved by providing a suitable filter layer structure, of the type mentioned above, optionally in combination with a appropriate formation of the active area can be achieved. hereby becomes the determination of spectral components in the incident radiation facilitates, since a spectral portion simplifies a single Radiation detector can be assigned. In particular, so can simplifies spectral components directly from the signals of the individual detectors be determined. Furthermore, the maximum wavelength of the a radiation detector preferably outside the detection range of the other radiation detector.

In In another preferred embodiment, there are two radiation detectors the detector arrangement is formed such that the detection range of the a radiation detector the detection range of the other radiation detector only partially or completely covered. With a partial overlap can the assignment of the spectral components to the respective radiation detector whereas with full coverage, the radiation detectors are relieved due to a waiver of the adjustment of the spectral sensitivity distributions or the detection areas may be cheaper can be made.

In In another preferred embodiment, there are two radiation detectors the detector arrangement is designed such that the spectral sensitivity distribution of a radiation detector of the detector arrangement with the spectral Sensitivity distribution of the other radiation detector, in particular only partially or completely, overlaps. Because of the overlap can the formation of a predetermined detection wavelength range, in which the detector arrangement is provided for radiation detection and / or is trained to be facilitated. In particular, can the detection wavelength range widened compared to the detection range of a single radiation detector be.

In In another preferred embodiment, there are two radiation detectors the detector arrangement designed such that the maximum wavelength of the Spectral sensitivity distribution of a radiation detector the detector arrangement of the maximum wavelength of the spectral sensitivity distribution the other radiation detector of the detector arrangement different is, wherein the spectral sensitivity distribution of the radiation detector the detector arrangement with the larger maximum wavelength with the spectral sensitivity distribution of the radiation detector the detector arrangement with the smaller maximum wavelength, in particular for wavelengths below the smaller maximum wavelength, at least in parts is congruent. Preferably covered the spectral sensitivity distribution of the radiation detector with the larger maximum wavelength one of the radiation detector with the smaller maximum wavelength completely.

One Radiation detector of the detector assembly can thus in, optionally via the total, detection area, another radiation detector generate a significant signal. For determination of spectral components from the incident radiation can after detecting the signals the detectors perform an arithmetic operation, such as forming the difference of the signals of the radiation detector and the other Radiation detector, performed become. From the signal of a radiation detector can, in particular immediately, a first spectral component and out of the arithmetic Operation obtained result can be a second spectral component be determined in the incident radiation.

In Another preferred embodiment is the detector arrangement for determining color fractions, in particular proportions of the primary colors red, Green and Blue provided in incident on the detector array radiation and / or trained.

By Detecting the signals at the various radiation detectors, the detection areas corresponding with preference to different colors can have information about the spectral color components in the incident on the radiation detector Radiation can be won.

In Another preferred embodiment of the invention is the detector arrangement for determining the color impression, such as the color location and / or the Color temperature, the incident radiation formed. The color location is usually by the color coordinates (x and y) are given in the CIE diagram.

Contains the incident radiation, for example, to an increased extent blue shares, it will be in a sensitive in this spectral range radiation detector a correspondingly high signal he generates, while in the radiation detectors for the red and green spectral range preferably correspondingly low signals are generated. By appropriate evaluation of the three mutually independent signals, which can preferably be assigned to the respective color component to be determined, signals can accordingly be obtained about the color locus of the incident radiation.

For example For example, the colorant determination detector arrangement has three radiation detectors on, wherein the first radiation detector for the detection of radiation in the blue spectral range, the second radiation detector for detection of radiation in the green Spectral range and the third radiation detector for detection provided by radiation in the red spectral range and / or is formed. Preferably, these radiation detectors are each only in one of These visible spectral ranges are significantly sensitive.

In Another preferred embodiment is the first radiation detector in the blue, green and red spectral sensitive, the second radiation detector only in the green and blue spectral range sensitive and the third radiation detector is sensitive only in the blue spectral range. As the first radiation detector both in blue, green As well as red spectral range generates a signal, while the Determination of spectral components, in particular blue and green components, from the signal of the detector arrangement to an immediate extraction the information about the color components of the generated in the individual radiation detectors Signals difficult, but the detectors of the detector array can cost-effective be manufactured because of an adaptation of the detection areas of the Single detectors, about about Filter layers, can be dispensed with each other.

The Radiation detectors thus generate all in the blue spectral range Signals. A radiation detector that not only in the assigned Detection area, but also in the other radiation detector assigned detection range generates a signal can, with the Signal of the other radiation detector are correlated. An im Radiation detector generated signal can by comparison with the Signal of the other, for the questionable spectral component also sensitive radiation detector be easily distinguished from an uncontrolled background noise.

The Color components can for example by means of forming differences from signals of discrete radiation detectors be won.

In a further preferred embodiment, the semiconductor body, in particular the active region, the functional layer and / or the filter layer structure, the first radiation detector and / or the second radiation detector contains a III-V semiconductor material, in particular a material from the III-V semiconductor material system In _x Ga _y Al _1-xy P, where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1 and x + y ≤ 1, preferably y ≠ 0 and / or y ≠ 1, In _x Ga _y Al _1-xy As, with 0 ≤ x ≤ 1, 0 ≤ y ≤ 1 and x + y ≤ 1, preferably y ≠ 0 and / or y ≠ 1, and / or In _x Ga _y Al _1-xy N, where 0 ≤ x ≤ 1, 0 ≤ y ≦ 1 and x + y ≦ 1, preferably y ≠ 0 and / or y ≠ 1.

III-V semiconductor materials can, as already mentioned above, be distinguished by particularly advantageous high internal quantum efficiencies. In the material system In _x Ga _y Al _1-xy P, it is possible to form in a simplified manner active regions or functional layers by means of which the entire visible spectral range can be covered.

Furthermore, a filter layer which contains a III-V semiconductor material, in particular of the material system In _x Ga _y Al _1-xy P or In _x Ga _y Al _1-xy As, for a filter layer structure simplified in a semiconductor body, in particular in a Semiconductor body on In _x Ga _y Al _1-xy P and / or In _x Ga _y Al _1-xy As base, monolithically integrated. As a result, a particularly compact and small design of the radiation detector with the filter layer structure can be achieved in a simplified manner.

In In another preferred embodiment, the functional layer is based in particular the semiconductor body, the filter layer structure and / or the active region of a radiation detector the detector arrangement and the functional layer, in particular the Semiconductor body, the filter layer structure and / or the active region, another Radiation detector of the detector array on the same semiconductor material system. The production of the radiation detectors of the detector arrangement can be so be simplified.

In a method according to the invention for determining various spectral components in a radiation incident on a detector arrangement having a plurality of radiation detectors, wherein a first radiation detector of the detector arrangement has a detection area assigned thereto, a second radiation detector of the detector arrangement has a detection area assigned to it and at least one of the radiation detectors Detector assembly comprises a semiconductor body with an active region provided for signal generation, first a first wavelength range for a first spectral component to be determined and a second wavelength range for a second, different from the first spectral component to be determined spectral component are determined. In this case, the detection range of the first radiation detector comprises the first wavelength range, the detection range of the second radiation detector includes the second wavelength range and the detection range of the second radiation detector overlaps with the first wavelength range. The radiation detectors are preferably arranged laterally next to each other and / or implemented discretely as individual detectors. Furthermore, the first and the second radiation detector preferably have a semiconductor body with an active region provided for signal generation.

thereupon are the, in particular due to the incident radiation, means of the first radiation detector and by means of the second radiation detector detected signals detected.

following is the signal originating from the first radiation detector and the second Radiation detector originating Signal performed an arithmetic operation that yields a result. From the result of the arithmetic operation, the second spectral Proportion and from the signal of the first radiation detector, in particular immediately, the first spectral component can be determined. Prefers For example, the second spectral portion and / or the second wavelength range includes wavelengths greater than those the first spectral component or the first wavelength range.

Prefers in the arithmetic operation the difference of the the second radiation detector generated signal and the means of the first generated radiation detector signal. The spectral Shares in the incident radiation can be detected by means of the first Radiation detector generated signal and by means of the result the previously formed difference. This is preferred the first spectral component in the incident radiation by means of the signal generated by the first radiation detector and / or the second spectral component in the incident radiation by means of the previously determined difference determined.

In a preferred embodiment covered the detection area of the second radiation detector the first Wavelength range Completely. The second radiation detector is thus for the first and for the second spectral component sensitive. On an adaptation of the detection area a radiation detector of the detector arrangement, such as through elaborate filtering, can be dispensed with with advantage. The detection area and / or the Sensitivity distribution can be essentially alone through the active region, in particular the functional layer, of the radiation detector be determined.

In a further preferred refinement, the semiconductor body, in particular the active region, of the first radiation detector and / or of the second radiation detector contains a III-V semiconductor material, in particular a material of the III-V semiconductor material system In _x Ga _y Al _1-xy P, with 0 ≤ x ≤ 1, 0 ≤ y ≤ 1 and x + y ≤ 1, preferably y ≠ 0 and / or y ≠ 1, In _x Ga _y Al _1-xy As, where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1 and x + y ≤ 1, preferably y ≠ 0 and / or y ≠ 1, and / or In _x Ga _y Al _1-xy N, where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1 and x + y ≤ 1, preferably y ≠ 0 and / or y ≠ 1.

such Semiconductor materials are, as already mentioned above, for a radiation detector particularly suitable in the visible spectral range.

Prefers is in the inventive method a detector arrangement according to the invention used so that those described above and below for the detector array Features also for the inventive method can be used and vice versa.

Above A number of preferred embodiments have been described. This was often done on two radiation detectors of the detector array Referenced. It should be noted that the features mentioned here not all in a single radiation detector pair of the detector array have to be realized. Rather, individual can Characteristics at different radiation detector pairs of the detector array be realized.

Further Features, advantageous embodiments and expediencies The invention will become apparent from the description of the following embodiments in conjunction with the figures.

It demonstrate:

1 a schematic sectional view of an embodiment of a detector arrangement according to the invention in 1A , a qualitative representation of the spectral sensitivity distribution of a radiation detector in 1B and in 1D the spectral sensitivity distribution of the detector array 1A with according to the table in 1C trained elements and

2 in 2A a schematic sectional view of a second embodiment of a detector arrangement according to the invention, in 2C the spectral sensitivity distribution of a detector arrangement according to 2A with according to the table in 2 B trained elements and in 2D Difference curves of the spectral sensitivity distributions of radiation detectors 2C ,

Same, similar and equally acting elements are in the figures with provided the same reference numerals.

In 1A is a first embodiment of a detector arrangement according to the invention schematically illustrated by a sectional view. The detector arrangement 10 includes a first radiation detector 1 , a second radiation detector 2 and a third radiation detector 3 , The radiation detectors 1 . 2 respectively. 3 The detector arrangement each comprise a semiconductor body 11 . 21 respectively. 31 , The semiconductor bodies of the radiation detectors each have an active region 12 . 22 respectively. 32 on, which is intended for signal generation and radiation reception. The active region of the respective radiation detector preferably comprises at least one functional layer, the radiation components from a radiation incident on the detector arrangement 40 can absorb. In particular, the active region can be formed by a functional layer.

The active area 12 . 22 respectively. 32 at least one radiation detector of the detector arrangement, preferably of the first, of the second and of the third radiation detector, contains a III-V semiconductor material and / or the active area of a first radiation detector of the detector arrangement is designed differently from that of a further radiation detector of the detector arrangement. Preferably, the active regions of the first radiation detector, the second radiation detector and the third radiation detector are made in pairs different from each other.

Furthermore, the active region of the first radiation detector, of the second radiation detector and / or of the third radiation detector is preferably between a first barrier layer 13 . 23 respectively. 33 and a second barrier layer 14 . 24 respectively. 34 arranged. The barrier layers of a radiation detector, such. B. the layers 13 and 14 of the first radiation detector 1 , preferably have different conductivity types (n-type or p-type). The semiconductor bodies of the radiation detectors are furthermore preferably each on a support 15 . 25 respectively. 35 arranged. The carrier advantageously mechanically stabilizes the respective semiconductor body arranged thereon. By way of example, the carrier may comprise the growth substrate on which the semiconductor body arranged on the carrier, in particular epitaxially grown, or the carrier may be formed by this growth substrate. The carriers 15 . 25 and 35 preferably contain a same material or are formed from the same materials.

The radiation detectors of the detector arrangement are preferably assigned different, in particular pairwise, different detection areas, ie areas in which the radiation detectors generate a significant signal. If the detector arrangement is designed to detect radiation over the visible spectral range, for example, the first radiation detector 1 associated with a detection area comprising the blue spectral range, the second radiation detector 2 associated with a detection area comprising the green spectral range and the third radiation detector 3 associated with a detection area that includes the red spectral range. The detection areas are preferably matched to one another in such a way that a detection area comprising a smaller wavelength overlaps with, in particular only, the adjacent longer-wavelength detection area. In this way, the detection of radiation over a coherent detection wavelength range, for example the visible spectral range, can be achieved in a simplified manner with signal generation that is significant over substantially the entire detection wavelength range. The detection range of the respective radiation detector can be determined by the formation of the functional layer of the active region. Expediently, the functional layers of radiation detectors which have different detection areas are designed differently.

The functional layers of radiation detectors, which are provided for different detection areas, preferably have different band gaps and / or thicknesses. The band gap essentially defines the wavelength range absorbed by the incident radiation. In particular, the bandgap defines an upper limit of this wavelength range. The detection range, in particular an upper limit wavelength of the detection range, can thus be set via the band gap of the functional layer. By choosing the thickness of the functional layer, the proportion of the incident radiation 40 absorbed radiation power and thus the signal strength generated in the respective radiation detector can be set specifically. The radiation detectors are preferably matched to one another such that their respective spectral sensitivity distributions assume the same maximum values. The comparison in the individual radiation detectors generated signals and the determination of various spectral components in the on the detector array 10 incident radiation 40 can be so relieved.

To those in the active areas 12 . 22 respectively. 32 To be able to detect generated electrical signals, the radiation detectors preferably have a first electrical contact 16 . 26 respectively. 36 and a second electrical contact 17 . 27 respectively. 37 on. The first and the second contact are special preferably on opposite sides of the carrier 15 . 25 respectively. 35 arranged. The first and second contacts are electrically connected to the respective active region. The active region is preferably arranged between the first and the second contact. For this purpose, if the carrier contains a semiconductor material, such as GaAs, it may be doped to increase the conductivity.

The radiation detectors are preferably arranged laterally next to one another. In particular, the radiation detectors can 1 . 2 and 3 on a common carrier element 100 be arranged. The carrier element 100 may for example be designed as part of a housing body, in particular a plastic housing body of an optoelectronic device, or as a printed circuit board. A housing body protects the radiation detector chips (a carrier with the semiconductor body arranged thereon) from harmful external influences. On a circuit board, the radiation detectors can be electrically contacted, such as by the contacts 17 . 27 respectively 37 and 16 . 26 respectively 36 be electrically connected to the tracks of the circuit board.

Shares of the on a radiation entrance side 18 . 28 respectively. 38 of the respective radiation detector in the semiconductor body 11 . 21 , respectively. 31 of the respective radiation detector 1 . 2 , respectively. 3 incoming radiation 40 can be absorbed according to the band gap of the functional layer of the respective area. The subsequently generated electron-hole pairs contribute to the signal of the radiation detectors. The wavelength dependence of the generated signal determines the spectral sensitivity distribution of the respective radiation detector. The sensitivity distribution of the individual radiation detectors preferably has a maximum at a maximum wavelength, which expediently lies in the detection area assigned to the respective radiation detector.

In 1B the dependence of the spectral sensitivity distribution R on the wavelength λ of the incident radiation for a single radiation detector is qualitatively shown. The spectral sensitivity distribution 101 has a maximum 106 at the maximum wavelength λ _m and a short-wave limit λ _a and a long-wave limit wavelength λ _b on. The detection range of the radiation detector is limited by the wavelengths λ _a and λ _b .

High energy Shortwave radiation can also be used in the detection of longer wavelength Radiation provided active areas or functional layers absorbed and generate a signal accordingly. By means of a filter layer structure, the at least one filter layer comprises and radiation with a wavelength smaller than the band gap the functional layer of the active region corresponding wavelength or smaller than the maximum wavelength can absorb signal generation due to short-wave radiation according to the absorbed in the filter layer short-wave Radiation fraction can be reduced. The detection range of the respective Radiation detector can, optionally in combination with a Functional layer of a suitable band gap, so to be determined spectral component to be adjusted. The filter layer structure is preferred monolithic in the semiconductor body integrated and between the radiation entrance side of the semiconductor body and the active region of the radiation detector is arranged.

In the present embodiment, the second radiation detector 2 and the third radiation detector 3 a filter layer structure 29 respectively. 39 on. The filter layer structure 39 of the third radiation detector has a first filter layer 391 and a second filter layer 392 which preferably have different band gaps and thicknesses. The filter layer structure makes it easier to reduce signal generation in active regions of radiation detectors provided for longer-wave radiation in the short-wave range-smaller than the maximum wavelength. Shortwave radiation is increasingly absorbed in the filter layer structure and thus can only generate signals in the active region to a reduced extent.

On the part of the first contact of the respective radiation detector, which is arranged on the side of the semiconductor body opposite to the carrier, the semiconductor body can be formed by a contact layer 160 . 260 respectively. 360 be completed. The contact layer has advantageous electrical contact properties for the first contact.

For III-V semiconductor materials based radiation detectors for the visible spectral range is due to the easily achievable high internal quantum efficiency particularly the material system In _x Ga _y Al _1-xy P. Especially for the active area of this material system is particularly suitable.

For the detection of differently colored spectral components, in particular portions of the primary colors red, green and blue, in the incident radiation are semiconductor bodies for the radiation detectors, which have elements which according to the in 1C shown table are particularly suitable. The carrier 15 . 25 respectively. 35 may each be given by an n-GaAs growth substrate on which the semiconductor body 11 . 21 respectively. 31 grown epitaxially. Preferably, the semiconductor body is based on the material system In _0.5 (Ga _1-x Al _x ) _0.5 P with 0 ≦ x ≦ 1, which is characterized by good lattice matching to a GaAs growth substrate distinguishes. The band gap of a semiconductor layer made of this material system can be adjusted via the Al content x.

In the table below 1C D denotes the thickness, E _G the band gap relevant for the absorption, in particular the direct band gap, and λ _G the wavelength corresponding to this band gap.

The filter layer structure 29 has a filter layer which in terms of thickness and composition corresponding to the active area 12 of the first radiation detector is formed. The same applies to the first filter layer 391 of the third radiation detector 3 , The second filter layer 392 the filter layer structure 39 of the third radiation detector 3 is in thickness and composition according to the active area 22 formed of the second radiation detector. A filter layer of a radiation detector having a detection region which, compared to that of a further radiation detector, comprises larger wavelengths, is accordingly designed in terms of composition and thickness in accordance with the functional layer of the further radiation detector.

The spectral sensitivity distribution of the individual radiation detectors of a detector arrangement designed in this way is shown in FIG 1D shown schematically. For the 1D was the spectral sensitivity distribution of a detector array according to 1A simulating the simulation of the table in 1C appropriate data were used. In 1D For example, the wavelength dependence of the responsivity of the generated photocurrent in amperes per watt of the incident radiant power on the wavelength of the radiation incident on the detector array is plotted in nm.

In 1D are the spectral sensitivity distribution 101 of the first radiation detector 1 , the spectral sensitivity distribution 102 of the second radiation detector 2 and the spectral sensitivity distribution 103 of the third radiation detector 3 shown.

The detection area of the first radiation detector 1 ranges from including λ _{a, 1} ≈ 400 nm up to and including λ _{b, 1} ≈ 600 nm, that of the second radiation detector 2 from including λ _{a, 2} ≈ 480 nm up to and including λ _{b, 2} ≈ 650 nm and that of the third radiation detector 3 from including λ _{a, 3} ≈ 550 nm up to and including λ _{b, 3} ≈ 675 nm.

Thus, apart from the region between 675 nm and 700 nm, the detector arrangement substantially covers the entire visible spectral range that passes through the curve 104 showing the sensitivity of a brightly adapted human eye according to the CIE standard. The detection areas of the radiation detectors overlap with each other. In particular, the detection range of the longest wavelength radiation detector overlaps 3 with that of the radiation detector 1 , which is intended for the shortest wavelength radiation. This overlap may, where appropriate, by otherwise forming the active zone of the radiation detector 1 or appropriate filtering can be avoided. The determination of spectral components in the incident radiation 40 can be so relieved.

The spectral sensitivity distributions 101 . 102 and 103 each have a maximum at a maximum wavelength λ _{m, i} (i = 1, 2, 3). The first radiation detector 1 is assigned to the blue spectral range, the second radiation detector 102 the green spectral range and the third radiation detector 103 the red spectral range. In particular, the maximum wavelengths are λ _{m, 1} ≈ 490 nm, λ _{m, 2} ≈ 555 nm and λ _{m, 3} ≈ 610 nm in the respective radiation detectors associated spectral or detection areas. The short-wave edge of the spectral sensitivity distributions of the second radiation detector 2 and the third radiation detector 3 is formed for wavelengths smaller than the respective maximum wavelength by absorbing wavelengths from the incident radiation smaller than the maximum wavelength in the filter layer structure of these radiation detectors. Preferably, the spectral sensitivity distributions are formed through the filter layer such that two spectral sensitivity distributions with adjacent maximum wavelengths intersect at a value that is less than half the maximum value. This is the case in the present training example. Half the maximum value is about 0.15 A / W. In particular, the filter layer structure determines the short-wave limit of the detection range of the respective radiation detector. Since only comparatively low sensitivities can be achieved in the material system In _x Ga _y Al _1-xy P in the blue spectral range, an additional filter layer structure for shaping the short-wave edge of the sensitivity distribution can be dispensed with in the case of the first radiation detector.

by virtue of the vote of the radiation detectors on different colored spectral ranges can from the signals detected by the discrete radiation detectors immediate information about color components obtained in the incident on the detector array radiation become. Further, the color impression can be determined.

Furthermore, the radiation detectors of the detector arrangement are preferably matched to one another such that they have substantially the same maximum values. This can be done by suitable Ausbil tion of the active region, in particular the functional layer of the respective radiation detector can be achieved. In the present exemplary embodiment, the three radiation detectors essentially have the common maximum value of 0.3 A / W.

The semiconductor body 31 the radiation detector provided for the long-wave radiation 3 has a considerable thickness of about 5 μm according to the above table. This considerable thickness is due to the filter layer structure which serves to tune the detection areas and which absorbs wavelengths from wavelength ranges which are undesirable for signal generation.

It should be noted that not only the filter layer structure alone can serve to shape the short-wave edge of the spectral sensitivity distribution of the radiation detector. Rather, the barrier layers arranged with respect to the active region on the radiation inlet side can also be provided for filtering. For this purpose, the barrier layers of the radiation detectors of the detector arrangement have different thicknesses (compare the table in FIG 1C ). In the trained for longer-wave radiation radiation detectors 2 and 3 shortwave radiation is thus increasingly absorbed in the respective barrier layers.

2 shows in 2A a schematic sectional view of a second embodiment of a detector arrangement according to the invention, in 2C the spectral sensitivity distribution of a detector arrangement according to 2A with according to the table in 2 B trained elements and in 2D Difference curves of the spectral sensitivity distributions of radiation detectors 2C ,

The detector arrangement according to the second embodiment again comprises a first radiation detector 1 a second radiation detector 2 and a third radiation detector 3 , In essence, the embodiment corresponds to 2A the first embodiment.

In contrast to the first embodiment, the second radiation detector 2 and the third radiation detector 3 on the filter layer structures 29 respectively. 39 waived. The third radiation detector 3 is sensitive over the detection range of the second and the first radiation detector. The second radiation detector in turn is sensitive over the detection range of the first radiation detector, but insensitive in the detection range of the third. The detection regions of the first, the second and the third radiation detector can in particular have a common lower limit wavelength.

To spectral components of the incident radiation 40 By means of such a detector arrangement, differences can be formed from the spectral sensitivity distributions of the first, the second and the third radiation detector. Advantageously, the information about a first spectral component, the difference between the spectral sensitivity distribution of the second radiation detector and the first radiation detector and that about a second spectral component and the difference of the spectral sensitivity distribution of the third radiation detector with the spectral component can advantageously be obtained from the signal of the first radiation detector Sensitivity distribution of the second radiation detector that are obtained over a third spectral component.

In the in 2 B shown table are elements that are particularly suitable for semiconductor body of radiation detectors according to the second embodiment. D denotes the thickness, E _G the absorption, in particular direct, band gap, and λ _G the wavelength corresponding to this band gap.

The spectral sensitivity distribution of the individual radiation detectors of a detector arrangement designed according to this table is shown in FIG 2C shown schematically. For the 2C was the spectral sensitivity distribution of a detector array according to 2A simulated, the simulation of the 2 B appropriate data were used. In 2C For example, the wavelength dependence of the responsivity of the generated photocurrent in amperes per watt of the incident radiant power on the wavelength of the radiation incident on the detector array is plotted in nm.

In 2C are the spectral sensitivity distribution 101 of the first radiation detector, the spectral sensitivity distribution 102 of the second radiation detector and the spectral sensitivity distribution 103 of the third radiation detector according to a detector arrangement 2A shown. Furthermore, the sensitivity distribution of the brightly adapted human eye 104 with a maximum at about 555 nm.

The first radiation detector 1 points for the blue spectral range, since he according to the 1D is made, the same spectral sensitivity distribution as the detector 1D on. With the second and the third radiation detector, the filter layer structure was dispensed with, so that these detectors face each other 1D are also sensitive in shorter wavelength wavelength ranges.

In particular, the sensitive overlap keitsverteilungen the first, second and third radiation detector for wavelengths smaller than the maximum wavelength λ _{m, 1 of} the first radiation detector. Furthermore, the spectral sensitivity distributions of the first, the second and the third radiation detector for wavelengths smaller than λ _{m, 1 are} in the range 105 the spectral sensitivity distribution of the detector array 10 congruent.

The detection range of the first radiation detector extending from including the common short wavelength cutoff wavelength of the three radiation detectors λ _a ≈ 400 nm to λ _{b 1} ≈ 600 nm, that of the second radiation detector by including λ _a to including λ _{b, 2} ≈ 650 nm and that the third radiation detector of including λ _a to including λ _{b, 3} ≈ 675 nm. the peak wavelength of the spectral sensitivity distribution of the first radiation detector λ _{m, 1} lies nm at about 490, the peak wavelength λ _{m, 2} of the spectral sensitivity distribution 102 of the second radiation detector at about 525 nm and the maximum wavelength λ _{m, 3 of} the spectral sensitivity distribution 103 λm _{, 3} is therefore in the green spectral range, the detection range for which the second radiation detector is provided.

The individual radiation detectors thus have significant overlapping or even overlapping sensitivity distributions or detection ranges, which makes the assignment of spectral components to the respective detector signal more difficult. From a detector arrangement with the sensitivity distribution according to 2C although it is compared with a detector arrangement according to 1D makes it difficult to obtain information on spectral components in the simple radiation directly from the detector signals, but such radiation detectors can be manufactured more cost-effectively due to the omission of filter layer structures and consequently reduced growth times.

The determination of color components from the incident radiation may, in the detector arrangement according to 2A by means of forming differences of the signals generated in the radiation detectors due to the incident radiation. In this case, it is preferred to subtract from a spectral sensitivity distribution of a radiation detector, in particular exclusively that of a further radiation detector with a shorter-wavelength detection range. Preferably, the shorter-wavelength detection range of that of the radiation detector wavelength-related, in particular on the long-wavelength side of the two sensitivity distributions, the closest detection range.

In 2D are curves resulting from such difference formation shown. The curve 101 corresponds to the spectral sensitivity distribution of the first radiation detector 1 , Around the bend 112 to obtain the spectral sensitivity distribution of the first radiation detector 101 from the spectral sensitivity distribution of the second radiation detector 102 out 2C deducted. Around the bend 123 to obtain the spectral sensitivity distribution 102 of the second radiation detector from the spectral sensitivity distribution 103 subtracted from the third radiation detector. From the signal of the first radiation detector 101 a blue spectral component can be determined. The difference curve 112 has a maximum at λ _{D, 2} ≈ 540 nm and is intended to determine spectral components in the green spectral range. The difference curve 123 has a maximum at λ _{D, 2} ≈ 595 nm and is intended for the determination of spectral components in the red spectral range. The difference curve 123 overlaps with the difference curve 112 ,

The spectral sensitivity distribution 101 of the first radiation detector for the short-wave radiation overlaps with the difference curve 112 , The of the spectral sensitivity distribution 101 Covered wavelength range extends from 400 nm to 600 nm, that of the difference curve 112 covered area approximately from 450 nm to 665 nm and that of the difference curve 123 Covered wavelength range from about 540 nm to 650 nm. Apart from the range between 655 nm and 700 nm, the difference of the difference and the detection range of the first radiation detector, the entire visible spectral range is continuously covered.

The The invention is not by the description based on the embodiments limited. Much more For example, the invention includes every novel feature as well as every combination of features, in particular any combination of features in the claims includes, even if this feature or this combination itself not explicitly stated in the patent claims or exemplary embodiments is.

Claims (21)

Detector arrangement comprising a plurality of discrete radiation detectors ( 1 . 2 . 3 ), wherein - a first radiation detector ( 1 . 2 . 3 ) and a second radiation detector ( 1 . 2 . 3 ) of the detector arrangement ( 10 ) each have a semiconductor body ( 11 . 21 . 31 ) with an active area provided for radiation reception and signal generation ( 12 . 22 . 32 ) and each having one, the respective radiation detector associated detection area, - in which the semiconductor body at least one Radiation detector contains a III-V semiconductor material and / or - in which the active region of the first radiation detector is designed differently from the active region of the second radiation detector. Detector arrangement according to Claim 1, characterized in that a band gap and / or a thickness of a functional layer of the active region ( 12 . 22 . 32 ) of the first radiation detector ( 1 . 2 . 3 ) of a band gap or a thickness of a functional layer of the active region ( 12 . 22 . 32 ) of the second radiation detector ( 1 . 2 . 3 ) is different. Detector arrangement according to Claim 2, characterized in that the bandgap of the functional layer of the active region ( 12 . 22 . 32 ) of the first radiation detector ( 1 . 2 . 3 ) corresponding wavelength and / or the band gap of the functional layer of the active region ( 12 . 22 . 32 ) of the second radiation detector ( 1 . 2 . 3 ) corresponding wavelength in the visible spectral range. Detector arrangement according to Claim 2 or 3, characterized in that the bandgap of the functional layer of the active region ( 12 . 22 . 32 ) of the first radiation detector ( 1 . 2 . 3 ) and the band gap of the functional layer of the active region ( 12 . 22 . 32 ) of the second radiation detector ( 1 . 2 . 3 ) corresponding wavelength in different colored spectral ranges. Detector arrangement according to one of the preceding claims, characterized in that the detector arrangement ( 10 ) is sensitive over a coherent predetermined detection wavelength range. Detector arrangement according to one of the preceding claims, characterized in that the first radiation detector and the second radiation detector each have a respective spectral sensitivity distribution assigned to the respective radiation detector (US Pat. 101 . 102 . 103 ) having a maximum at a given maximum wavelength. Detector arrangement according to claim 6, characterized in that - at least one radiation detector ( 2 . 3 ) of the detector arrangement a in the semiconductor body ( 21 . 31 ) of this radiation detector monolithically integrated filter layer structure ( 29 . 39 ) with at least one filter layer ( 29 . 391 . 392 ), the filter layer structure absorbs radiation in a wavelength range of wavelengths smaller than the maximum wavelength of the spectral sensitivity distribution ( 102 . 103 ) of this radiation detector and - the filter layer structure between a radiation entrance side ( 18 . 28 . 38 ) of the semiconductor body and the active region. Detector arrangement according to claim 7, characterized in that the filter layer structure ( 39 ) a plurality of filter layers ( 391 . 392 ) having. Detector arrangement according to Claim 8, characterized in that the filter layers ( 391 . 392 ) of the filter layer structure ( 39 ) have different band gaps and / or thicknesses. Detector arrangement according to one of Claims 2 to 9, characterized in that the detection area of a radiation detector ( 1 . 2 . 3 ) of the detector arrangement of the band gap of the functional layer of a further radiation detector ( 1 . 2 . 3 ) includes the detector array corresponding wavelength. Detector arrangement according to one of claims 6 to 10, characterized in that the maximum wavelength of the sensitivity distribution ( 102 . 103 ) of a radiation detector ( 2 . 3 ) of the detector arrangement ( 10 ) within the detection range of a further radiation detector ( 1 . 2 ) of the detector array is located. Detector arrangement according to one of the preceding claims, characterized in that the detection area of a radiation detector ( 1 . 2 . 3 ) of the detector arrangement ( 10 ) the detection range of a further radiation detector ( 1 . 2 . 3 ) of the detector arrangement ( 10 ) only partially or completely covered. Detector arrangement according to one of Claims 6 to 12, characterized in that the spectral sensitivity distribution ( 101 . 102 . 103 ) of a radiation detector ( 1 . 2 . 3 ) of the detector arrangement ( 10 ) with the spectral sensitivity distribution ( 101 . 102 . 103 ) of a further radiation detector ( 1 . 2 . 3 ) of the detector arrangement, in particular only partially or completely, overlaps. Detector arrangement according to one of claims 6 to 13, characterized in that - the maximum wavelength of the spectral sensitivity distribution ( 101 . 102 . 103 ) of a radiation detector ( 1 . 2 . 3 ) of the detector arrangement ( 10 ) of the maximum wavelength of the spectral sensitivity distribution ( 101 . 102 . 103 ) of a further radiation detector ( 1 . 2 . 3 ) of the detector arrangement is different, - the spectral sensitivity distribution of the radiation detector of the detector arrangement with the larger maximum wavelength with that spectra len sensitivity distribution of the radiation detector of the detector array with the smaller maximum wavelength at least partially congruent runs. Detector arrangement according to one of the preceding claims, characterized in that the detector arrangement ( 10 ) for the determination of color components, in particular on the primary colors red, green and blue, in radiation incident on the detector arrangement ( 40 ) is provided and / or formed. Detector arrangement according to one of the preceding claims, characterized in that the detector arrangement ( 10 ) has a third radiation detector, wherein the first radiation detector ( 1 ) for the detection of radiation in the blue spectral range, the second radiation detector ( 2 ) for the detection of radiation in the green spectral range and the third radiation detector ( 3 ) is provided for the detection of radiation in the red spectral range and / or formed. Detector arrangement according to one of the preceding claims, characterized in that the semiconductor body ( 11 . 21 . 31 ), in particular the active area ( 12 . 22 . 32 ), the functional layer and / or the filter layer structure ( 29 . 39 ), the first radiation detector and / or the second radiation detector, a III-V semiconductor material, in particular a material of the III-V semiconductor material system In _x Ga _y Al _1-xy P with 0 ≤ x ≤ 1, 0 ≤ y ≤ 1 and x + y ≤ 1. Method for determining various spectral components in a detector arrangement ( 10 ) with a plurality of radiation detectors ( 1 . 2 . 3 ), wherein a first radiation detector of the detector arrangement has a detection area assigned to it, a second radiation detector of the detector arrangement has a detection area assigned to it and at least one of the radiation detectors of the detector arrangement comprises a semiconductor body with an active area provided for signal generation, characterized by the steps, a ) Defining a first wavelength range for a first spectral component to be determined and defining a second wavelength range for a second spectral component to be determined which is different from the first spectral component, wherein the detection range of the first radiation detector ( 1 ) comprises the first wavelength range, the detection range of the second radiation detector ( 2 ) comprises the second wavelength range and the detection range of the second radiation detector overlaps with the first wavelength range, b) detecting the signal generated by the first radiation detector and the signal generated by the second radiation detector, c) forming the difference of the second radiation detector ( 2 ) and by means of the first radiation detector ( 1 d) determining the first spectral component in the incident radiation by means of the signal generated by the first radiation detector and / or determining the second spectral component in the incident radiation by means of the difference formed in step c). A method according to claim 18, characterized in that the detection range of the second radiation detector ( 2 ) completely covers the first wavelength range. Method according to claim 18 or 19, characterized in that the semiconductor body ( 11 . 21 . 31 ), in particular the active area ( 12 . 22 . 32 ), the first radiation detector ( 1 . 2 . 3 ) and / or the second radiation detector ( 1 . 2 . 3 ) contains a III-V semiconductor material, in particular a material of the III-V semiconductor material system In _x Ga _y Al _1-xy P with 0 ≤ x ≤ 1, 0 ≤ y ≤ 1 and x + y ≤ 1. Method according to one of claims 18 to 20, characterized in that the detector arrangement comprises a detector arrangement ( 10 ) according to one of claims 1 to 17.