JP2012151111A - Method of forming structure in plastic substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a substrate which is used in a semiconductor device and characterized by a first surface and a second surface.SOLUTION: The method includes a step for providing a mold having a first template and/or a second template corresponding, respectively, to a first texture and a second texture, and a step for forming a substrate by injection molding a substrate material in the mold. This material is injection molded to create the first texture on the first surface and/or the second texture on the second surface. The first texture and/or the second texture facilitate extraction of light or trapping of light in a semiconductor device.

Description

  The present invention disclosed herein generally relates to semiconductor devices. More particularly, the present invention relates to the manufacture of injection molded substrates in semiconductor devices.

  Semiconductor materials are widely used as electroluminescent materials in organic light-emitting devices (OLED) and photovoltaic materials in organic photoelectric devices (OPV).

  OLEDs and / or OPVs typically include a semiconductor material layer to achieve their function. In OPV, for example, a semiconductor material that receives solar radiation generates excitons that are diffused through the semiconductor material layer. This is then separated into free charge carriers as electrons and holes, and electrode pairs are provided on both sides of the semiconductor material layer to collect free charge carriers and help generate current.

  Similarly, in an OLED, for example, when a voltage is applied across the semiconductor material layer, electrons and holes are injected from the individual electrodes. The electrons and holes recombine in the semiconductor material layer to form excitons, thereby emitting light.

  Thus, in the function of semiconductor devices such as OLEDs and OPVs, light management is a very important aspect that has a significant impact on the efficiency of such devices.

  In general, the refractive index of the semiconductor material layer is larger than that of the OLED and OPV substrates. In OLEDs, this refractive index difference causes the emitted light to be reflected off the substrate and returned through the layer of semiconductor material, thereby reducing the percentage of the emitted light that can be extracted. Also, due to the difference in refractive index between the substrate and the surrounding medium where the OLED is used, some light is reflected back into the substrate at the interface between the substrate and the surrounding medium. This further reduces the efficiency of the OLED. Similarly, in OPV, optical trapping is a major factor that affects its efficiency. Therefore, it is necessary to increase the optical path in the OPV in order to increase the absorption.

  In order to increase the efficiency of such devices, a lacquer layer having a light management texture is added to such devices at the interface between different refractive index materials. For example, an OLED may have a light extraction texture on a semiconductor material layer and a substrate or a lacquer layer deposited between the substrate and the surrounding medium, and an OPV device may have a lacquer deposited between the semiconductor material layer and the substrate. There may be a light trapping texture on the layer.

  However, adding a lacquer layer to OLEDs and OPVs increases the cost of manufacturing such devices. Also, the material of the lacquer layer tends to contaminate the semiconductor material layer with the solvent released during the manufacturing process. Furthermore, in OLEDs, the lacquer layer is provided on the substrate and therefore tends to be between the substrate and the encapsulating cover. This reduces the effectiveness of encapsulation and allows moisture to enter the OLED, thereby contaminating the device. Also, the presence of a lacquer layer is highly undesirable in areas where electrodes are deposited on the semiconductor layer. This is because the presence of lacquer in these areas can cause water or air to peel or penetrate through the lacquer.

  In light of the above, there is a need for improvements in current OPVs and OLEDs to eliminate one or more disadvantages of the prior art.

The present invention provides a method of manufacturing a substrate for use in a semiconductor device such as an OLED or OPV such that the substrate has a light extraction texture or a light trapping texture. The method includes performing injection molding to form a substrate by using a mold having a first template corresponding to the first texture and a second template corresponding to the second texture. The first texture and the second texture can serve as light trapping and / or light extraction textures.
When the substrate is manufactured using this method, it is not necessary to deposit an additional light extraction or light trapping layer on the substrate, thereby reducing the cost of the semiconductor device. In addition, since the substrate formed by injection molding can replace a commonly used glass substrate, the cost advantage is even greater. In one exemplary embodiment, when the substrate is used in an OLED, a mold having a template corresponding to both internal and external light extraction textures can be used. The use of such a substrate helps remove the two deposition processes corresponding to internal light extraction and external light extraction deposition from the semiconductor device manufacturing process, thereby reducing the cost of the semiconductor device.

  In an embodiment of the present invention, a method for manufacturing a substrate for use in a semiconductor device is provided, whereby the substrate is characterized by a first surface and a second surface. The method includes providing a mold having a first template corresponding to a first texture and / or a second template corresponding to a second texture. The method includes injection molding a material for forming a substrate in a mold to form a substrate, whereby the material is first texture on the first surface and / or second on the second surface. Injection molded to create two textures. The first texture and / or the second texture facilitate light extraction and / or light trapping in the semiconductor device in which the substrate is used.

  In some embodiments of the invention, a semiconductor device is provided. The semiconductor device includes an injection molded substrate having a first surface and a second surface. In this substrate, the first surface includes a first texture and / or the second surface includes a second texture. The first texture and / or the second texture are configured to facilitate light extraction and / or light trapping in the semiconductor device. The semiconductor device further includes a first electrode on the substrate, one or more semiconductor layers on the first electrode, and a second electrode on the one or more semiconductor layers. These layers are encapsulated between the substrate and the cover substrate to form a semiconductor device.

  In some embodiments of the invention, the refractive index of the substrate is substantially the same as or greater than the refractive index of the semiconductor layer or layers of the semiconductor device for optical uniformity.

  In some embodiments of the invention, the material for forming the substrate is selected from the group comprising plastic, polycarbonate, polyethylene terephthalate (PET), and polyethylene naphthalate (PEN).

  In another embodiment of the invention, the semiconductor device is an organic light emitting device (OLED), the substrate forms a base layer of the OLED, and the OLED has one or more semiconductor layers disposed on the substrate. .

  In yet another embodiment of the invention, the second texture can prevent reflection of light into the one or more semiconductor layers at the interface between the substrate and the one or more semiconductor layers, and the first texture Prevents reflection of light into the substrate at the interface between the substrate and the surrounding medium.

  In another embodiment of the present invention, the semiconductor device is an organic photoelectric device (OPV), the substrate forms an OPV base layer, and the OPV is one or more semiconductors disposed on the substrate. Has a layer.

  In yet another embodiment of the present invention, the second texture can prevent reflection of light into the substrate at the interface between the substrate and the one or more semiconductor layers, and the first texture is the substrate and the surrounding medium. Prevents reflection of light into the surrounding medium at the interface between

  The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention may best be understood with reference to the following description taken in conjunction with the accompanying drawings. These drawings and the associated description are provided to illustrate some embodiments of the invention and do not limit the scope of the invention.

FIGS. 1a and 1b illustrate the stack of layers in an exemplary OLED and an exemplary OPV according to the state of the art prior to the present invention (ie prior art).

FIG. 2 illustrates an exemplary mold used for injection molding of a substrate in accordance with an embodiment of the present invention.

FIG. 3 illustrates an exemplary view of a first die and a second die of a mold used for injection molding a substrate according to an embodiment of the present invention.

FIGS. 4a, 4b, 4c and 4d illustrate exemplary textures that can be provided in a die of a mold according to some embodiments of the present invention.

FIG. 5 illustrates an exemplary texture formed on the first surface of the substrate in accordance with an embodiment of the present invention.

FIGS. 6a and 6b illustrate the stack of layers in an exemplary OLED and an exemplary OPV, respectively, according to an embodiment of the present invention.

FIG. 7 is a flowchart illustrating an exemplary process for forming a texture on a substrate by injection molding in accordance with an embodiment of the present invention.

FIG. 8 is a flowchart illustrating an exemplary method of manufacturing a semiconductor device according to another embodiment of the present invention.

  Those skilled in the art will appreciate that the elements in the figures are illustrative for the sake of brevity and clarity and that the dimensions are not necessarily accurate. For example, some dimensions of elements in the figures are exaggerated relative to other elements to improve the understanding of the invention.

  If there is a structure in the specification that is not illustrated in the drawing, such structure should not be construed as omitted from the specification.

  Before describing the present invention in detail, it should be noted that the present invention utilizes a combination of method steps and apparatus components associated with a method of manufacturing a semiconductor device. Accordingly, apparatus components and method steps are represented in the drawings using conventional symbols and represent only those portions that are relevant to an understanding of the present invention in detail. This is so as not to obscure the disclosure of the present invention with details that are obvious to those skilled in the art.

  The specification concludes with claims that define the features believed to be novel of the invention, which will be better understood from the following description and the accompanying drawings.

  Although detailed embodiments of the present invention are disclosed herein, it is to be understood that the disclosed embodiments are merely exemplary of the invention, and that the invention can be embodied in various forms. . Accordingly, specific structural and functional details disclosed herein should not be construed as limiting the scope of the claims, but are the basis of the claims and are intended to be practiced in various forms of the invention. It should be construed as a representative basis for the teaching given to vendors. Further, the terms and phrases presented herein are not to be construed as limiting, but are to be construed as providing an understandable description of the invention.

  In this specification, “one” means one or more. “Other” means “at least a second”, and “includes” and / or “have” is an open term that allows the addition of other elements. “Coupled” or “operably linked” means joined, but need not be direct or mechanical.

  Referring now to the drawings, FIG. 1a shows a stack of layers in an exemplary OLED 100a known in the state of the art prior to the present invention. OLED 100a is shown to include an external light extraction layer 102, a transparent substrate 104, an internal light extraction layer 106, a first electrical contact 108, one or more semiconductor layers 110 and 112, a second electrical contact 114 and a cover substrate 116. The internal light extraction layer 106, the first electrode 108, the one or more semiconductor layers 110 and 112, and the second electrode 114 are sealed between the transparent substrate 104 and the cover substrate. Each layer of the OLED 100a is formed in an adjacent layer by a method such as coating except for the external light extraction layer 102 and the internal light extraction layer 106, and the present invention is carried out.

  For illustration purposes, OLED 100a is shown to include only the layers relevant to the description of the present invention. However, it should be understood that the invention is not limited to the layers listed above. In some cases, OLED 100a may include additional layers to increase efficiency or improve reliability without departing from the scope of the present invention.

  The transparent substrate 104 provides strength to the OLED 100a and also serves as a light emitting surface of the OLED 100a when in use. Examples of the transparent substrate 104 include, but are not limited to, glass, flexible glass, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and other transparent or translucent materials.

  First electrical contact 108 and second electrical contact 114 are used to apply a voltage across one or more semiconductor layers 110 and 112. The first electrical contact 108 can be implemented with, for example, a transparent conductive oxide (TCO). TCO is a doped metal oxide, examples of TCO are aluminum-doped zinc oxide (AZO), indium zinc oxide (IZO), boron-doped zinc oxide (BZO), gallium-doped oxide. Including but not limited to zinc (GZO), fluorine doped tin oxide (FTO) and indium doped tin oxide (ITO). Further, the second electrical contact 114 can be implemented with a metal (eg, calcium, aluminum, gold, or silver) that has an appropriate work function for injecting charge carriers.

  The one or more semiconductor layers 110 and 112 can be implemented with an organic electroluminescent material (eg, a light emitting polymer, a deposited low molecular weight material, a light emitting dendrimer, or a molecularly doped polymer).

The incident light from the high refractive index material to the interface with the lower refractive index material or medium is for all incident angles greater than the critical angle θ _c defined by θ _c = sin ^-1 (n ₂ / n ₁ ) Total reflection (TIR) results (n ₁ and n ₂ are the refractive indices of the high and low refractive index materials, respectively). For the same reason, when the light emitted by the semiconductor layer 110 or 112 reaches the interface with the transparent substrate 104, a considerable amount of light is reflected back to the semiconductor layers 110 and 112.

  The presence of an internal light extraction layer 106 with a texture that can change the direction of propagation of light emitted by one or more semiconductor layers 110 or 112 at the interface with the substrate 104 is a reflection of light (or TIR) into the OLED 100a. ) Help reduce. The texture on the inner light extraction layer 106 may include a shape having dimensions in the order of the wavelength of the light to facilitate changes in the propagation direction of the emitted light by diffraction. The texture on the inner light extraction layer 106 may include a shape having a dimension larger than the wavelength of the light in order to facilitate the change in the propagation direction of the emitted light by refraction. Thus, the presence of textured internal light extraction layer 106 serves as an absorber and scatterer that removes or reduces TIR and further increases the efficiency of the OLED. Similarly, the external light extraction layer 102 reduces or eliminates TIR at the interface between the transparent substrate 104 and the surrounding medium.

  In other exemplary embodiments, a hole transport layer (not shown) may also be deposited on the first electrical contact 108 prior to depositing the semiconductor layer 110. The hole transport layer can enhance the flow of holes from the first electrical contact 108 to the semiconductor layer 110, thereby increasing the efficiency of the OLED 100a.

  Similarly, in yet another exemplary embodiment, an electron transfer layer (not shown) may also be deposited on the semiconductor layer 112 prior to depositing the second electrical contact 114. The electron transfer layer can enhance the flow of electrons from the second electrical contact 114 to the semiconductor layer 112 and thereby increase the efficiency of the OLED 100a.

  Referring now to FIG. 1b, a stack of layers in an exemplary OPV 100b is shown according to an embodiment of the present invention. OPV 100b is shown to include a transparent substrate 118, a light trapping layer 120, a first electrical contact 122, one or more semiconductor layers 124 and 126, a second electrical contact 128 and a cover substrate 130.

  In the OPV 100b, light strikes one or more semiconductor layers 124 and 126 and allows generation of electricity through the semiconductor layers 124 and 126. This electricity is extracted to the external circuit by first and second electrical contacts 122 and 128. In OPV 100b, an optical trapping layer 120 is provided to increase the optical path of light sent to OPV 100b.

  The presence of a lacquer layer is desirable for light extraction and light trapping in devices such as OLEDs and OPVs. However, the use of a lacquer layer increases the manufacturing costs of such devices. Also, the presence of the lacquer layer is undesirable in the area where the substrate and cover substrate are joined and in the area where electrical contacts are deposited on the semiconductor layer, because the presence of the lacquer material used in the lacquer layer is delaminated or lacquered This is because water or air may enter through the layers. This can cause corrosion and adversely affect the implementation of such devices (OLED or OPV). The present invention provides a solution to these problems by providing a substrate that includes light extraction and / or light trapping texture. This allows devices such as OLEDs and OPVs to control the light extraction and light trapping layer manufacturing costs. This also minimizes water, air and other contaminant ingress problems previously caused by the presence of light extraction and light trapping layers.

  Referring now to FIG. 2, an exemplary mold 200 used for substrate injection molding in accordance with an embodiment of the present invention is shown in FIG. One skilled in the art will appreciate that the mold 200 may include more or fewer components or regions than those shown in FIG. The mold 200 may include components or regions not shown and not relevant to various embodiments of the present invention.

  The mold 200 is shown to include a first die 202a, a second die 202b, and a nozzle 204. According to the present invention, the material forming the substrate can be injected in a molten state into the cavity formed between the first die 202a and the second die 202b via the nozzle 204. Thereafter, the molten material forming the substrate is cooled to form the substrate. The mold 200 may include a built-in cooling mechanism, such as a cooling jacket / cavity, to facilitate cooling. The texture is formed on the substrate based on the cavity configuration. In one embodiment, the texture formed on the substrate may be a light extraction and / or light trapping texture. The material for forming the substrate is usually a thermoplastic material. Examples of materials include, but are not limited to, plastic, polycarbonate, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and other transparent thermoplastic materials. Examples of materials for the mold 200 include, but are not limited to, iron, steel, stainless steel, aluminum alloy, and brass.

  Turning to FIG. 3, an exemplary view of a first die 202a and a second die 202b is shown in FIG. 3 in accordance with an embodiment of the invention. The first die 202a is shown to include a first template 302 and a portion 204a of the nozzle 204 corresponding to the first texture. Similarly, the second die 202b is shown to include a second template 304 and a portion 204b of the nozzle 204 corresponding to the second texture. Examples of materials for the first die 202a and the second die 202b include, but are not limited to, iron, steel, stainless steel, aluminum alloy, and brass.

  The substrate formed using the mold 200 is characterized by a first surface and a second surface. The material for forming the substrate is injection molded in the mold 200, whereby a first texture is formed on the first surface of the substrate and a second texture is formed on the second surface of the substrate. In some embodiments, the material for forming the substrate may be shaped such that the texture is formed only on one surface of the substrate.

  In practical applications, for example in OLEDs, the first texture and the second texture facilitate light extraction, allowing the first and second surfaces to act as an external light extraction layer and an internal light extraction layer, respectively. Similarly, for OPV, the first texture and the second texture may facilitate light trapping.

  For example, in OLED, the light propagation direction must be changed to facilitate light extraction. The texture provided to the substrate will change the light propagation direction. Texture can cause changes in the direction of light propagation by diffraction or refraction. Textures having dimensions in the order of the wavelength of light usually change the light propagation direction by diffraction. Examples of textures that change the light propagation direction by diffraction include, but are not limited to, 1D diffraction gratings and 2D diffraction gratings. Textures having dimensions larger than the wavelength of light usually change the light propagation direction by refraction. Examples of textures that change the light propagation direction by refraction include, but are not limited to, lenses, cones, and pyramids.

  Typically, textures that facilitate external and internal light extraction can help to change the light propagation direction by diffraction or refraction, thereby removing or reducing TIR. However, textures that facilitate internal light extraction can often change the direction of light propagation by diffraction, and textures that facilitate external light extraction are often light propagation by refraction. The direction can be changed.

  In addition to the second texture, the second die 202b of the mold 200 can also include one or more gutter-shaped grooves. The shape of these gutters corresponds to an electronic circuit that can be accommodated in the shape formed by one or more grooves on the second surface of the substrate.

  These one or more grooves are configured to accommodate electronic circuitry normally required for large area semiconductor devices. The conductivity provided by the TCO-based electrode layer of a semiconductor device is often insufficient, leading to a voltage drop in large area semiconductor devices. This voltage drop can be prevented by providing an electronic circuit in addition to the TCO layer. The electronic circuit can be in the form of a metal wire or busbar grid with high conductivity, or a circuit that can provide a current path across the entire surface of the electronic grid wire or substrate and TCO layer.

  At the same time, however, the second texture and the top surface of the electronic circuit should be of similar height to ensure that there is no gap between the surface of the second texture and the next layer. This can be maintained by providing one or more gutter-like grooves in the second die 202b of the mold 200 along with the second texture. The one or more grooves are formed so as not to protrude from the surface of the second texture and fully correspond to the shape of the electronic circuit, thereby providing a substantially uniform surface for subsequent deposition. This helps to prevent non-uniformities in the thickness of the next layer. In some embodiments, the one or more grooves are designed to have a width in the range of 20-100 microns and a depth in the range of 2-30 microns.

  Providing one or more grooves in the second die 202b helps provide a higher aspect ratio groove, resulting in a narrower grid line that is less noticeable. Furthermore, the additional step of providing one or more grooves is omitted, making the process simple and low cost.

  Continuing, FIG. 4a is an illustration of an example die 402 that includes an example template 404 corresponding to an example texture. FIG. 4a also shows section 406 of template 402. Section 406 is utilized in FIGS. 4b, 4c and 4d to describe exemplary textures in accordance with some embodiments of the present invention.

  The die 402 is essentially similar to the first die 202a and the second die 202b described using FIG. The die 402 may also be part of a mold used to form a substrate according to the present invention.

  In accordance with an embodiment of the present invention, section 406 is shown to include four inverted pyramids that provide template 404 with a corresponding texture. In this case, the texture formed on the surface of the substrate is in the form of a plurality of pyramids. However, those skilled in the art will appreciate that the template may be any other such texture that provides light extraction / light trapping features without departing from the scope of the present invention.

  The textures illustrated in FIGS. 4b, 4c and 4d can change the light propagation direction using refraction. However, other such textures that provide light extraction / light trapping features, such as lenses, 1D diffraction gratings, 2D diffraction gratings, etc., can be applied as well without departing from the scope of the present invention. Will be understood by those skilled in the art.

  In one embodiment, the radius 'a' of the individual pyramids in the texture ranges from 5 microns to 250 microns, and the height 'b' of the individual pyramids in the texture ranges from 10 microns to 500 microns, the apex angle 'c' can range from 30 degrees to 150 degrees. However, those skilled in the art will appreciate that the individual pyramids may be of other suitable dimensions that allow the necessary functions to be performed without departing from the scope of the present invention.

  In another embodiment, individual pyramids are separable from adjacent individual pyramids at a distance 'd' along the x-axis of section 406 and a distance 'e' along the y-axis. In one embodiment, the distances 'd' and 'e' may range from 0 to 200 microns. However, those skilled in the art will appreciate that adjacent individual pyramids can be separated by other suitable distances that allow the necessary functions to be performed without departing from the scope of the present invention. .

  In one embodiment, when using diffraction to change the light propagation direction, the texture dimensions are typically in the range of 200 nm to 400 nm. Similarly, the distance between adjacent textures along the x-axis and y-axis ranges from 500 nm to 700 nm. However, the texture may be of other dimensions and is separated from the adjacent texture by other suitable distances that allow the texture to achieve the required function without departing from the scope of the present invention. One skilled in the art will understand that this may be the case.

  Turning to FIG. 5, an exemplary texture formed on an exemplary first surface 504 of an exemplary substrate 502 is shown in accordance with an embodiment of the present invention. For the understanding of the present invention, the texture is shown only on the first surface 504 of the substrate 502. However, those skilled in the art will appreciate that a texture can also be formed on the second surface 506 of the substrate 502. It should also be understood that the elements in this figure are illustrative for the sake of brevity and clarity and that the dimensions are not necessarily accurate. For example, the texture dimensions shown in the figures may be exaggerated with respect to the substrate 502 to improve understanding of the present invention.

  In accordance with an embodiment of the present invention, FIG. 6a shows a stack of layers in an exemplary OLED 600a. The OLED 600a is shown to include a substrate 602 having a first surface 604 and a second surface 606. The first surface 604 includes a first texture 608 and the second surface 606 includes a second texture 610. The first surface 604 including the first texture 608 serves as an external light extraction layer, and the second surface 606 including the second texture 610 serves as an internal light extraction layer. Therefore, the OLED 600a formed according to the present invention can function without providing an external and light extraction layer separately.

  The other layers in the stack of layers in the OLED 600a are similar to those of the OLED 100a described in FIG. 1a, with the first electrical contact 108, one or more semiconductor layers 110 and 112, the second electrical contact 114 and the cover substrate. Including 116.

  Some examples of OLED600a are organic light emitting diode (OLED), white organic light emitting diode (W-OLED), active matrix organic light emitting diode (AMOLED), simple matrix organic light emitting diode (PMOLED), flexible organic light emitting diode (FOLED) ), Stacked organic light emitting diode (SOLED), tandem organic light emitting diode, transparent organic light emitting diode (TOLED), top light emitting organic light emitting diode, bottom light emitting organic light emitting diode, fluorescent doped organic light emitting diode (F-OLED) and Including but not limited to phosphorescent organic light emitting diodes (PHOLED).

  The substrate 602 provides strength to the OLED 600a and also serves as the light emitting surface of the OLED 600a when in use. Examples of materials that can be used to form the substrate 602 include, but are not limited to, plastic, polycarbonate, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and other such transparent thermoplastic materials. Further, the substrate 602 is optically transparent, that is, the substrate 602 allows the passage of incident light.

  In one embodiment, the substrate 602 can be formed of a material having a refractive index that is substantially the same as or greater than the one or more semiconductor layers 110 and 112. Examples of such materials include but are not limited to polyethylene naphthalate (PEN). This improves optical uniformity, ie, removes or minimizes the TIR of light that occurs when the refractive index of the substrate 602 is less than the refractive index of the one or more semiconductor layers 110 and 112 and returns to the OLED 600a. If the refractive index of the material of the substrate 602 is substantially the same as or greater than the refractive index of the one or more semiconductor layers 110 and 112, the first surface 604 of the substrate 602 provides a first light extraction. One texture 610 may be provided and the second surface 608 may not include a texture that provides internal light extraction. This is because the TIR has already been removed or minimized.

  In one embodiment, the second texture 610 on the second surface 606 allows the substrate 602 to change the light propagation direction by diffraction, thereby helping to remove or reduce TIR, thereby allowing light to enter. Pass the second surface 606. An example of a second texture 610 that changes the direction of light propagation by diffraction includes a texture having dimensions in the order of the wavelength of light.

  In another embodiment, the second texture 610 on the second surface 606 allows the substrate 602 to change the light propagation direction by refraction, thereby helping to remove or reduce the TIR, thereby reducing the light Passes through the second surface 606. An example of the second texture 610 that changes the light propagation direction by refraction includes a texture having a dimension larger than the wavelength of light.

  Similarly, the first texture 608 reduces or eliminates TIR at the interface between the substrate 602 and the surrounding medium. However, in many cases, the first texture 608 changes the light propagation direction by refraction. An example of such a first texture 608 includes a texture having a dimension larger than the wavelength of light.

  For example, in the case of light extraction, the light emitted by the one or more semiconductor layers 110 and 112 and reaching the second texture 610 can pass through this and reach the substrate 602. The second texture 610 refracts light and prevents the light from being reflected back to the one or more semiconductor layers 110 and 112. The first texture 608 also allows light to pass through the substrate 602 and enter the surrounding medium. The first texture 608 refracts light and prevents the light from being reflected back to the OLED 600a.

  In the exemplary embodiment, a hole transport layer (not shown) may be deposited on the first electrical contact 108 before depositing the one or more semiconductor layers 110 and 112. The hole transport layer can enhance the flow of holes from the first electrical contact 108 to the semiconductor layer 110, thereby increasing the efficiency of the OLED 600a.

  Similarly, in yet another exemplary embodiment, an electron transfer layer (not shown) may be deposited on the semiconductor layer 112. The electron transfer layer can enhance the flow of electrons from the second electrical contact 114 to the semiconductor layer 112, thereby increasing the efficiency of the OLED 600a.

  In FIG. 6a, the OELD 600a is shown as a flat layer stack. However, in another embodiment, the second texture that provides internal light extraction may propagate through the OLED 600a, so that all layers may contain similar textures.

  Referring now to FIG. 6b, a stack of layers in an exemplary OPV 600b is shown according to an embodiment of the present invention. OPV 600b is shown to include a substrate 612 having a first surface 614 and a second surface 616. The second surface 616 includes a second texture 618 and the first surface 614 does not include a texture. A second surface 616 comprising a second texture 618 serves as a light trapping layer. However, those skilled in the art will appreciate that a texture can be formed on the first surface 614 of the substrate 612. The OPV 600b formed according to the present invention can function without a separate optical trapping layer.

  The other layers in the stack of layers in OPV 600b are similar to those of OPV 100b described in FIG. 1b, and include a first electrical contact 122, one or more semiconductor layers 124 and 126, a second electrical contact 128 and a cover substrate. Including 130.

  In the OPV 600b, light striking the semiconductor layers 124 and 126 allows generation of electricity through the semiconductor layers 124 and 126, and this electricity is extracted to external circuitry by the first and second electrical contacts 122 and 128. In OPV 600b, a second texture 618 is provided to increase the optical path of the light sent to OPV 600b. For example, in the case of light trapping, light that enters the substrate 612 from the surrounding medium and reaches the second texture 618 passes through it and reaches one or more semiconductor layers 124 and 126. The first texture 608 refracts light and prevents it from being reflected back to the surrounding medium.

  Referring now to FIG. 7, a texture formation process 700 is provided for forming a texture on a substrate (eg, substrate 602). To illustrate the method 700, reference is made to FIGS. 2, 3, 4, 5, and 6, but it will be understood that the method 700 may be implemented in other suitable environments. Further, the present invention is not limited to the order of steps listed in method 700. Furthermore, it will be apparent to those skilled in the art that the method 700 may include one or more additional steps that further enhance the effectiveness of the method 700 but are not essential to the method 700 in accordance with the present invention.

  The method begins at step 702. At step 704, a mold (eg, mold 200) is provided. The mold 200 includes a first die 202a and a second die 202b. The first die 202a includes a first template 302 corresponding to the first texture, and the second die 202b includes a second template 304 corresponding to the second texture. When the first die 202a and the second die 202b are closed, the mold 200 is formed, thereby forming a cavity in the mold. The cavity is defined with a first texture on one side and a second texture on the other side.

  In one embodiment, the first texture and the second texture may be light extraction and / or light trapping textures. In another embodiment, the mold 200 can be provided with only one texture, ie, the first texture or the second texture. The first texture on the first die 202a and the second texture on the second die 202b may be generated using any method selected from the group of engraving, milling, lithography, etc. .

Thereafter, in step 706, the material forming the substrate (eg, substrate 602) is injection molded in mold 200. In one embodiment, the material for forming the substrate 602 is injected into the mold 200 through the nozzle 204 in a molten state. Once the cavity in mold 200 is filled with material, pressure is then maintained to compensate for material shrinkage. Examples of materials for forming the substrate 602 include, but are not limited to, plastic, polycarbonate, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and other such transparent thermoplastic materials. In one embodiment, the substrate 602 can be formed using a material having a refractive index that is substantially the same as or greater than the one or more semiconductor layers 110 and 112.
This improves optical uniformity, ie, removes or removes the TIR of light returning to the OLED 600a (which occurs when the refractive index of the substrate 602 is less than the refractive index of the one or more semiconductor layers 110 and 112). Minimize. When the refractive index of the material of the substrate 602 is substantially the same as or greater than the refractive index of the one or more semiconductor layers 110 and 112, the first surface 604 of the substrate 602 provides a first external light extraction. With one texture 610, the second surface 608 may not include a texture that provides internal light extraction. This is because the TIR has already been removed or minimized.

  Thereafter, in step 708, the substrate 602 is formed. When the molten material contacts the mold 200, it begins to cool. The molten material is at a temperature above the glass transition temperature, and the mold 200 is at a temperature lower than the glass transition temperature of the molten material. The molten material cools and solidifies, and the mold 200 maintains its temperature. In addition, the mold 200 is typically formed of a metallic material having a high thermal conductivity, allowing the molten material to cool rapidly and form the substrate 602. Also, the method 700 can reduce cycle time because the mold temperature is more or less maintained and no additional cooling steps are required.

  In another embodiment, additional coolant may be used to cool the molten material. The mold 200 may include a built-in cooling mechanism, such as a cooling jacket / cavity, to facilitate cooling.

  The method 700 then ends at step 710.

  Referring now to FIG. 8, an exemplary method for manufacturing an OLED (eg, OLED 600a) is provided. To illustrate the method 800, reference is made to FIGS. 2, 3, 4, 5, 6, and 7, but it will be understood that the method 800 may be implemented in other suitable environments. Further, the present invention is not limited to the order of steps listed in method 800. Furthermore, it will be apparent to those skilled in the art that the method 800 may include one or more additional steps that further enhance the effectiveness of the method 800 but are not essential to the method 800 according to the present invention.

  For illustrative purposes, the method 800 has been described with reference to OLEDs and light extraction, but it will be appreciated by those skilled in the art that the present invention can be implemented for light management purposes such as light trapping in OPVs. It will be clear.

  The method begins at step 802. In step 804, a textured substrate is provided. For example, the substrate on which the texture is formed may be the substrate 602. In one embodiment, the textured substrate can be prepared using the method 700 described using FIG.

  Thereafter, in step 806, a first electrical contact is deposited on the textured substrate. For example, the first electrical contact may be the first electrical contact 108 and can be deposited on the second surface 606 of the substrate 602. The first electrical contact 108 can be deposited by using various methods (eg, dip coating, spin coating, doctor blade, spray coating, screen printing, sputtering, glass mastering, photoresist mastering, electroforming, and evaporation). It is. In one embodiment, the first electrical contact 108 serves as the anode.

  Thereafter, in step 808, a first semiconductor layer is deposited. For example, the first semiconductor layer may be the semiconductor layer 110. In one embodiment, the semiconductor layer 110 is a conductive type semiconductor layer, which can facilitate transport of holes from the first electrical contact, ie, the anode. Examples of materials used for the semiconductor layer 110 include, but are not limited to, polyaniline. The semiconductor layer 110 can be deposited by using various methods (eg, dip coating, spin coating, doctor blade, spray coating, screen printing, sputtering, glass mastering, photoresist mastering, electroforming, and evaporation). .

  Thereafter, in step 810, a second semiconductor layer is deposited. For example, the second semiconductor layer may be the semiconductor layer 112. In one embodiment, the semiconductor layer 112 is an emission-type semiconductor layer, which can facilitate the transport of electrons from the cathode. Examples of materials used for the semiconductor layer 112 include, but are not limited to, polyfluorene. The second semiconductor layer can be deposited by using various methods (eg, dip coating, spin coating, doctor blade, spray coating, screen printing, sputtering, glass mastering, photoresist mastering, electroforming, and evaporation). is there.

  Thereafter, in step 812, a second electrical contact is deposited on the second semiconductor layer. For example, the second electrical contact may be the second electrical contact 114 and may be deposited on the semiconductor layer 112. The second electrical contact 114 can be deposited by using various methods (eg, dip coating, spin coating, doctor blade, spray coating, screen printing, sputtering, glass mastering, photoresist mastering, electroforming, and evaporation). It is. In one embodiment, the second electrical contact serves as the cathode.

  Thereafter, in step 814, a cover substrate (eg, cover substrate 116) is provided on the second electrical contact 114, whereby the cover substrate 116 is bonded to the substrate 602, and between the cover substrate 116 and the substrate 602. The first electrical contact 108, the one or more semiconductor layers 110 and 112, and the second electrical contact 114.

  The method 800 then ends at step 816.

  The various embodiments described above provide a method of manufacturing a substrate and a method of manufacturing a semiconductor device having several advantages. One of several advantages is that the substrate is responsible for light management, so that additional light extraction / light trapping layers are excessive for the requirements of the semiconductor device, thus reducing the number of layers in the semiconductor device It is possible to do. This helps to reduce the cost of the semiconductor device. In addition, the substrate formed by injection molding according to the present invention can replace a commonly used glass substrate. This leads to additional cost savings. Another advantage is that the absence of a light extraction / light trapping layer reduces the chance of encapsulation delamination. This further reduces or eliminates moisture or moisture intrusion into the semiconductor device, thereby preventing contamination of the semiconductor device.

  The light extraction / light trapping layer also emits several gases and other fluids during the manufacturing process or during use of the semiconductor device at high temperature conditions. This gas and other fluids tend to corrode electrical contacts. Accordingly, another advantage of the present invention is to prevent corrosion of electrical contacts.

  While the present invention has been disclosed based on preferred embodiments, various modifications and improvements will become apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention is not limited by the above examples, but is understood in the broadest sense permitted by law.

  All documents referred to herein are hereby incorporated by reference.

Claims (15)

A method of manufacturing a substrate used in a semiconductor device, comprising:
The substrate is characterized by a first surface and a second surface, the method comprising:
Providing a mold having at least one of a first template corresponding to a first texture and a second template corresponding to a second texture;
Forming a substrate by injection molding a material so as to form the substrate in the mold;
The material is injection molded to create at least one of the first texture on the first surface and the second texture on the second surface, and at least one of the first texture and the second texture. And a method of facilitating at least one of light extraction and light trapping in the semiconductor device. The method of claim 1, wherein the refractive index of the substrate is substantially the same as or greater than the refractive index of one or more semiconductor layers of the semiconductor device for optical uniformity. The method of claim 1, wherein the material for forming the substrate is selected from the group comprising plastic, polycarbonate, polyethylene terephthalate (PET), and polyethylene naphthalate (PEN). The semiconductor device is an organic light emitting device (OLED), the substrate forms a base layer of the OLED, and the OLED has one or more semiconductor layers disposed on the substrate. The method described in 1. The second texture can prevent light from being reflected into the one or more semiconductor layers at an interface between the substrate and the one or more semiconductor layers, and the first texture can be The method of claim 4, wherein reflection of light into the substrate at an interface between surrounding media is prevented. The semiconductor device is an organic photoelectric device (OPV), the substrate forms a base layer of the OPV, and the OPV has one or more semiconductor layers disposed on the substrate. The method described in 1. The second texture can prevent reflection of light into the substrate at an interface between the substrate and the one or more semiconductor layers, and the first texture is between the substrate and the surrounding medium. The method of claim 6, wherein reflection of light into the surrounding medium at the interface is prevented. A method of manufacturing a semiconductor device, the method comprising:
Providing a mold having at least one of a first template corresponding to a first texture and a second template corresponding to a second texture;
Injection molding the material to form a substrate having a first surface and a second surface in the mold;
Providing a first electrode on the substrate;
Providing one or more semiconductor layers on the first electrode;
Providing a second electrode on the one or more semiconductor layers;
Providing a cover substrate enclosing the first electrode, the one or more semiconductor layers, and the second electrode between the substrate and the cover substrate;
The material is injection molded to create at least one of the first texture on the first surface and the second texture on the second surface, and at least one of the first texture and the second texture. And a method of facilitating at least one of light extraction and light trapping in the semiconductor device. 9. The method of claim 8, wherein the refractive index of the substrate is substantially the same as or greater than the refractive index of the one or more semiconductor layers of the semiconductor device for optical uniformity. 9. The method of claim 8, wherein the material for forming the substrate is selected from the group comprising plastic, polycarbonate, polyethylene terephthalate (PET), and polyethylene naphthalate (PEN). 9. The method of claim 8, wherein the semiconductor device is an organic light emitting device (OLED) and the substrate forms a base layer of the OLED. The second texture can prevent light from being reflected into the one or more semiconductor layers at an interface between the substrate and the one or more semiconductor layers, and the first texture can be 9. The method of claim 8, wherein reflection of light into the substrate at an interface between surrounding media is prevented. 9. The method of claim 8, wherein the semiconductor device is an organic photoelectric device (OPV) and the substrate forms a base layer of the OPV. The second texture can prevent reflection of light into the substrate at an interface between the substrate and the one or more semiconductor layers, and the first texture is between the substrate and the surrounding medium. 9. The method of claim 8, wherein reflection of light into the surrounding medium at the interface is prevented. An injection molded substrate having a first surface and a second surface;
A first electrode provided on the second surface of the substrate;
One or more semiconductor layers provided on the first electrode;
A second electrode provided on the one or more semiconductor layers;
A cover substrate enclosing the first electrode, the one or more semiconductor layers and the second electrode between the substrate and the cover substrate;
The first surface comprises a first texture and / or the second surface comprises a second texture;
The semiconductor device, wherein the first texture and the second texture facilitate at least one of light extraction and light trapping in the semiconductor device.