CN1988192A - Flexible single layer white light quantum point electroluminescence device and its preparing method - Google Patents

Abstract

This invention discloses a flexible single layer white light quantum point electroluminescent device and its manufacturing method, which takes ZnS, ZnS:Cu/ZnS, ZnS : Mn/ZnS three color quantum points as the primary luminescent materials and PMMA as the film material to coat the raw material on ITO surface of the PET substrate rotationally to make the material to a film in a certain thickness and get a device in the following structure: ITO/PMMA : ZnS, ZnS : Cu/ ZnS, ZnS : Mn/ZnS(y nm) /Al(z nm), in which, the device is in a single layer structure without preparing luminescent layers of three basic colors and etching them separately and has the character of simple technology, flexible bending and good repeatability.

Description

Flexible single layer white light quantum point electroluminescence device and preparation method thereof

[technical field]

Patent of the present invention relates to a kind of novel flat-plate escope spare---flexible single layer white light quantum point electroluminescence device and preparation method thereof.

[background technology]

The flexible el display device is that pliable and tough flexible and material with good light permeability is replaced the glass substrate of commonplace components as substrate, compares with the common electrical electroluminescence device, has light, thin, anti-vibration and characteristics such as shock-resistant.Therefore, the flexible el display device has important application prospects as a kind of novel solid plateization and flexibility display device in portable display device, military field.Though its development rapidly, panchromatic demonstration problem is a key factor of its industrialization process of restriction always.

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 provides a kind of preparation method and device of flexible single layer white light quantum point electroluminescence device in order to overcome the deficiencies in the prior art.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 utilize the good film forming of polymer, realize simple layer, simple in structure, luminous uniform plate flexible single layer white light quantum point electroluminescence device.

Flexible 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 of PET (polyethylene terephthalate) substrate; Luminescent layer is dissolved in the ZnS of PMMA (polymethyl methacrylate), ZnS:Cu/ZnS, ZnS:Mn/ZnS core/shell structure quantum dot; Metal A l negative electrode.

The present invention also provides a kind of preparation method of above-mentioned flexible single layer white light quantum point electroluminescence device, comprising:

(1) after the ito anode that will be etched into 5mm*60mm bar shaped PET substrate 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) PMMA is dissolved in the chloroformic solution of 1～2mg/ml, with ZnS, ZnS:Cu/ZnS, the ZnS:Mn/ZnS quantum dot is 1: 1: 1～3: 1: 1 by mass ratio, is dissolved in the chloroformic solution of 1～2mg/ml, 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) use polytrifluorochloroethylene that device is encapsulated, cut out the polytrifluorochloroethylene film, then it is covered the one side that is coated with functional layer that has prepared, expose ito anode and Al negative electrode, with epoxide-resin glue sealing all around, move in the desiccator and left standstill 10～30 minutes, make the epoxy resin adhesive curing;

(5) 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 flexible single layer white light quantum point electroluminescence device.

Advantage of the present invention and good effect: the invention provides a kind of flexible 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 flexible single layer white light quantum point electroluminescence device is 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.In addition, this flexible white light quanta point electroluminescent device has realized that substantially flexible demonstration and anti-vibration and resistance to impact are stronger, and device has been carried out simple package, and has compared the packaging working life and improved 13 times, and this illustrates that these encapsulation means are effective.

[description of drawings]

Fig. 1 is a flexible single layer white light quantum point electroluminescence device concrete structure schematic diagram;

[embodiment]

The present invention is with ZnS, ZnS:Cu/ZnS, ZnS:Mn/ZnS three look quantum dots are the main body luminescent material, and utilize the good film forming of polymer P MMA, as filmogen, utilize rotation to apply polymer P MMA on the ITO surface of pet layer, raw material is made certain thickness film, obtain having the device of following structure: ITO/PMMA:ZnS, ZnS:Cu/ZnS, ZnS:Mn/ZnS (y nm)/Al (z nm); Wherein, 30≤y≤60nm; 60≤z≤150nm, ZnS in the luminescent layer, ZnS:Cu/ZnS, the mass ratio of ZnS:Mn/ZnS quantum dot is between 1: 1: 1～3: 1: 1.

Embodiment 1:

(1) after the ito anode that will be etched into 5mm*60mm bar shaped PET substrate 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) PMMA is dissolved in the chloroformic solution of 1mg/ml, with ZnS, ZnS:Cu/ZnS, the ZnS:Mn/ZnS quantum dot is 2: 1: 1 by mass ratio, is dissolved in the chloroformic solution of 1.5mg/ml, adopts 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) use polytrifluorochloroethylene that device is encapsulated, cut out the polytrifluorochloroethylene film, then it is covered the one side that is coated with functional layer that has prepared, expose ito anode and Al negative electrode, with epoxide-resin glue sealing all around, move in the desiccator and left standstill 30 minutes, make the epoxy resin adhesive curing;

(5) 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 white light quantum point electroluminescent device.

Embodiment 2:

(1) after the ito anode that will be etched into 5mm*50mm bar shaped PET substrate 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) PMMA is dissolved in the chloroformic solution of 2mg/ml, with ZnS, ZnS:Cu/ZnS, the ZnS:Mn/ZnS quantum dot is 3: 1: 1 by mass ratio, is dissolved in the chloroformic solution of 1.5mg/ml, adopts 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) use polytrifluorochloroethylene that device is encapsulated, cut out the polytrifluorochloroethylene film, then it is covered the one side that is coated with functional layer that has prepared, expose ito anode and Al negative electrode, with epoxide-resin glue sealing all around, move in the desiccator and left standstill 25 minutes, make the epoxy resin adhesive curing;

(5) 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 white light quantum point electroluminescent device.

Claims (4)

1, a kind of flexible single layer white light quantum point electroluminescence device is characterized in that this luminescent device is made up of following each layer successively from bottom to top:

1) ito anode of PET substrate;

2) luminescent layer is dissolved in the ZnS of PMMA, ZnS:Cu/ZnS, ZnS:Mn/ZnS three look quantum dots;

3) Al cathode layer.

2, flexible single layer white light quantum point electroluminescence device according to claim 1, it is characterized in that ZnS in the luminescent layer, ZnS:Cu/ZnS, the mass ratio of ZnS:Mn/ZnS three look quantum dots is between 1: 1: 1～3: 1: 1, PMMA is a filmogen, and light emitting layer thickness y is 30≤y≤60nm.

3, flexible single layer white light quantum point electroluminescence device according to claim 1 is characterized in that Al cathode layer thickness z is 60≤z≤150nm.

4, the preparation method of the described flexible single layer white light quantum point electroluminescence device of a kind of claim 1 is characterized in that this method may further comprise the steps:

(1) after the ito anode that will be etched into 5mm*60mm bar shaped PET substrate 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) PMMA is dissolved in the chloroformic solution of 1～2mg/ml, with ZnS, ZnS:Cu/ZnS, the ZnS:Mn/ZnS quantum dot is 1: 1: 1～3: 1: 1 by mass ratio, is dissolved in the chloroformic solution of 1～2mg/ml, 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) use polytrifluorochloroethylene that device is encapsulated, cut out the polytrifluorochloroethylene film, then it is covered the one side that is coated with functional layer that has prepared, expose ito anode and Al negative electrode, with epoxide-resin glue sealing all around, move in the desiccator and left standstill 10～30 minutes, make the epoxy resin adhesive curing;

(5) 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 flexible single layer white light quantum point electroluminescence device.

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