Single layer white light quantum point electroluminescence device and preparation method thereof
[technical field]
The present invention relates to a kind of novel flat-plate escope spare---single layer white light quantum point electroluminescence device and preparation method thereof.
[background technology]
Quantum dot is accurate zero-dimension nano semi-conducting material, and it is made of a small amount of atom or atomic group, and three dimension scale is at 1~10nm usually.Because the influence of size quantum effect and dielectric confinement effect demonstrates unique physics and chemical characteristics such as fluorescent characteristic, makes quantum dot have broad application prospects at aspects such as optoelectronics and biology.Advantages such as quanta point electroluminescent device has low-power consumption, high efficiency, response speed is fast and in light weight can the large tracts of land film forming, is a kind of photonic device with huge learning value and good commercial promise.More options ZnS coats the luminescent layer of CdSe quantum dot as electroluminescent device in the world aspect material, but the toxicity of cadmium (Cd) is bigger, can enter human body through food, water or air, and human body is produced serious toxic action.Given this, European Union forbade using cadmium materials such as (Cadmium) by hazardous substance illegal instruction (RoHS) in the electronic motor equipment in electronic product from July 1st, 2006.So developing novel environment friendly quantum electric material is the direction of quanta point electroluminescent device development.
Simultaneously, mostly the method for traditional in the world acquisition white light is to realize by sandwich construction, promptly adopt the method that three kinds of luminescent layers of red, green, blue are piled up, obtain white light by mixing three primary colors, the weak point of this kind method shows as complicated process of preparation, difficult the grasp, cost is higher, and the white light colourity of device easily changes along with the variation that adds driving voltage, and in addition because sandwich construction easily causes self-absorption, general quantum efficiency is all lower.
[summary of the invention]
The objective of the invention is in order to overcome the deficiencies in the prior art, and a kind of preparation method and device of single layer white light quantum point electroluminescence device are provided.The present invention is the luminescent layer material with the three primary colors quantum dot that does not contain cadmium toxic components such as (Cd) and have a good thermal stability, and utilizes the good film forming of polymer, realizes simple layer, plate single layer white light quantum point electroluminescence device simple in structure.
Single layer white light quantum point electroluminescence device provided by the invention is characterized in that this luminescent device is made up of following each layer successively from bottom to top: the ito anode conductive glass layer; Luminescent layer is the ZnS that is dissolved in PVK, ZnS:Cu, ZnS:Mn three look quantum dots; Metal A l negative electrode.
The present invention is with ZnS, ZnS:Cu, and ZnS:Mn three look quantum dots are the main body luminescent material, and utilize
The preparation method of a kind of above-mentioned single layer white light quantum point electroluminescence device provided by the invention comprises:
(1) after the ito glass that will be etched into the 5mm*60mm bar shaped cleans in cleaning agent repeatedly, soaks and ultrasonic cleaning, dried for standby in IR bake at last through isopropyl alcohol, acetone and chloroformic solution respectively again;
(2) PVK is dissolved in the chloroformic solution of 1~2mg/ml, with ZnS, ZnS:Cu, the ZnS:Mn quantum dot is 1: 1: 1~3: 1: 1 by mass ratio, is dissolved in the chloroformic solution of 1~2mg/ml, and two kinds of solution are mixed, and adopts the spin coating method film forming; Low speed 1000~1400rpm, film formation time 10~20s, high speed 3000~4000rpm, film formation time 10~30s was placed on drier interior 3~10 hours after finishing;
(3) preparation of Al negative electrode is adopted to divide on tungsten alloy stove silk and is hung the long AL silk of about 1~2cm, by the bar shaped mask plate, and vacuum evaporation skim bar shaped Al on luminescent layer, vacuum degree is greater than 8 * 10
-4Pa., evaporation current is 10~30A, and evaporation time is 10~20 minutes;
(4) with bar shaped ito anodes all in the above-mentioned device of making one termination dc power anode, all bar shaped Al negative electrode one termination dc power cathodes obtain the dot matrix single layer white light quantum point electroluminescence device.
Advantage of the present invention and good effect: the invention provides a kind of single layer white light quantum point electroluminescence device, this white light parts adopts the simple structure of individual layer, need not to prepare respectively the luminescent layer of three kinds of primary colours, and they are carried out loaded down with trivial details photoetching process etc. respectively, have that preparation technology is simple, the characteristics of good reproducibility; This single layer white light quantum point electroluminescence device is very suitable for the backlight as this class display spare, and it also has littler power consumption than general monochromatic light backlight simultaneously, has higher contrast and brightness.And it is combined with comparatively ripe microelectronics etching color filter membrane technology, then be expected to access panchromatic demonstration.
[description of drawings]
Fig. 1 is a single layer white light quantum point electroluminescence device concrete structure schematic diagram;
[embodiment]
The present invention is with ZnS, ZnS:Cu, ZnS:Mn three look quantum dots are the main body luminescent material, and utilize the good film forming of polymer P VK (polyvinylcarbazole), as filmogen, utilize rotation to apply polymer P VK on electro-conductive glass ITO surface, to make certain thickness film, obtain having the device of following structure: ITO/PVK:ZnS, ZnS:Cu, ZnS:Mn (y nm)/Al (z nm); Wherein, 30≤y≤60nm; 60≤z≤150nm, ZnS in the luminescent layer, ZnS:Cu, the mass ratio of ZnS:Mn quantum dot is between 1: 1: 1~3: 1: 1.The respective material molecular formula is as follows:
Embodiment 1:
(1) after the ito glass that will be etched into the 5mm*60mm bar shaped cleans in cleaning agent repeatedly, soaks and ultrasonic cleaning, dried for standby in IR bake at last through isopropyl alcohol, acetone and chloroformic solution respectively again;
(2) PVK is dissolved in the chloroformic solution of 1.2mg/ml, with ZnS, ZnS:Cu, ZnS:Mn quantum dot are to be dissolved at 2: 1: 1 in the chloroformic solution of 1.5mg/ml by mass ratio, and two kinds of solution are mixed, and adopt the spin coating method film forming; Low speed 1100rpm, film formation time 20s, high speed 3000rpm, film formation time 30s was placed on drier interior 10 hours after finishing;
(3) preparation of Al negative electrode is adopted to divide on tungsten alloy stove silk and is hung the long Al silk of about 2cm, by the bar shaped mask plate, and vacuum evaporation skim bar shaped Al on luminescent layer, vacuum degree is greater than 8 * 10
-4Pa., evaporation current is about 30A, and evaporation time is about 12 minutes;
(4) with bar shaped ito anodes all in the above-mentioned device of making one termination dc power anode, all bar shaped Al negative electrode one termination dc power cathodes obtain the dot matrix single layer white light quantum point electroluminescence device.
Embodiment 2:
(1) after the ito glass that will be etched into the 5mm*50mm bar shaped cleans in cleaning agent repeatedly, soaks and ultrasonic cleaning, dried for standby in IR bake at last through isopropyl alcohol, acetone and chloroformic solution respectively again;
(2) PVK is dissolved in the chloroformic solution of 1.7mg/ml,, with ZnS, ZnS:Cu, ZnS:Mn quantum dot are to be dissolved at 3: 1: 1 in the chloroformic solution of 2mg/ml by mass ratio, adopt the spin coating method film forming; Low speed 1300rpm, film formation time 20s, high speed 3000rpm, film formation time 30s was placed on drier interior 8 hours after finishing;
(3) preparation of Al negative electrode is adopted to divide on tungsten alloy stove silk and is hung the long Al silk of about 2cm, by the bar shaped mask plate, and vacuum evaporation skim bar shaped Al on luminescent layer, vacuum degree is greater than 8 * 10
-4Pa., evaporation current is about 30A, and evaporation time is about 15 minutes;
(4) with bar shaped ito anodes all in the above-mentioned device of making one termination dc power anode, all bar shaped Al negative electrode one termination dc power cathodes obtain the dot matrix single layer white light quantum point electroluminescence device.