CN203466191U - Array substrate and display device - Google Patents

Abstract

The utility model provides an array substrate and a display device, and belongs to the technical field of organic electroluminescence display. The array substrate and the display device can solve the problem that an existing array substrate is low in light out-coupling efficiency. The array substrate comprises an organic electroluminescence device, wherein the organic electroluminescence device comprises a first electrode layer, a second electrode layer, and a luminescent layer arranged between the first electrode layer and the second electrode layer, and the first electrode layer is a transparent electrode layer and is arranged on a planarization layer mingled with metal micro-nano particles.

Description

A kind of array base palte and display unit

Technical field

The utility model belongs to ORGANIC ELECTROLUMINESCENCE DISPLAYS technical field, is specifically related to a kind of array base palte and display unit.

Background technology

The basic structure of organic electroluminescence device (OLED) comprising: anode layer, cathode layer and be clipped in anode layer and cathode layer between " luminescent layer ", wherein, luminescent layer is one or more layers organic layer.Under applied voltage effect, electronics and hole are injected into organic layer from cathode direction and anode direction respectively, then move and the compound generation exciton that meets in " luminescent layer ", and the energy of exciton is with the form decay of light, i.e. radiation bright dipping.

Organic electroluminescence device can be divided into top emission type (Top emission) and end emission type (Bottom emission) according to bright dipping mode.Wherein, light is end emission type from thin-film transistor (TFT) and planarization layer (being also a first electrode layer) side outgoing, and its first electrode layer should be transparent (if ITO is indium tin oxide) electrode; For top emission type, the first electrode layer being positioned on planarization layer is nontransparent reflecting electrode (reflective material such as silver, aluminium), and the second electrode lay is transparent material, i.e. light direction.Organic electroluminescence device with respect to top transmitting, the impact that the organic electroluminescence device of end emission type is limited to TFT generally has less aperture opening ratio, and in order to reach the luminosity that possesses use value, although the brightness that can improve organic electroluminescence device by improving the modes such as voltage, this often causes negative effect to the life-span of device and material.Therefore for the preparation of the organic electroluminescence device of end emission type, the requirement of the performance index such as the life-span of its material and luminous efficiency will be higher.

In the luminescence process of organic electroluminescence device, the loss of energy mainly exists aspect two: first aspect is that injected carrier is coupled when luminous in luminescent layer, not all Implantation Energy all changes photon into, part exciton energy is depleted through nonradiative transition processes such as lattice vibration, deep-level impurity transition, can describe this process with internal quantum efficiency.Second aspect is anode layer and the interface total reflection such as substrate, substrate and air that occurs in organic electroluminescence device, occur near the surface plasma loss of the anode layer of organic electroluminescence device and the waveguide mode at luminescent layer interface and metal electrode etc., cause the light that sends from luminescent layer after the above-mentioned sandwich construction of experience, only have about 20% left and right can appear device and enter into air and seen by us.This process can be described by external quantum efficiency, embodiment be the efficiency that light is extracted from device, i.e. light extraction efficiency or light extraction efficiency.Wherein, by the performance improvement of material, at present internal quantum efficiency approaches 100% device and can realize in theory, but material category is very limited; And reduce waveguide mode loss by manufacture surface micro-structure on ITO electrode, by being applied to, photonic crystal or microlens array in substrate of glass, reduce total internal reflection, manufacture the negative electrode of fold to reduce its surface plasma loss and to utilize optical microcavity structure etc., although these technology can increase considerably the light extraction efficiency of device, but photonic crystal and the method such as formation periodicity or quasi periodicity microstructure graph on negative electrode, it often adopts nanometer replica technology, and preparation technology and difficulty are larger.And microcavity effect easily causes departing from and the shortcoming such as visible angle narrows down of glow color.

Utility model content

Technical problem to be solved in the utility model comprises, for existing organic electroluminescence device above shortcomings, provides a kind of array base palte and display unit that can improve illumination efficiency of organic electroluminescent device.

The technical scheme that solution the utility model technical problem adopts is a kind of array base palte, include organic electroluminescence devices, described organic electroluminescence device comprises: the first electrode layer, the second electrode lay and be arranged on the luminescent layer between the first electrode layer and the second electrode lay, described the first electrode layer is transparent electrode layer, and it is arranged on the planarization layer of doping metals micro-nano granules.

In the planarization layer of array base palte of the present utility model, doped with metal micro-nano particle, therefore it strengthens the luminous efficiency of organic electroluminescence device, and then improve the light emission rate of array base palte.

Preferably, described metal micro-nano granular materials be in gold, silver, aluminium any one.

Preferably, the form of described metal micro-nano particle be in spherical, prism-shaped, cubic, nucleocapsid structure any one.

Preferably, the particle diameter of described metal micro-nano particle is between 1nm-100nm.

Preferably, described the first electrode layer is anode layer, its material be in tin indium oxide, zinc oxide, indium oxide gallium zinc any one.

Further preferably, above-mentioned array base palte also comprises thin-film transistor, and the drain electrode of described thin-film transistor is connected by running through its top contact via hole of planarization layer and the first electrode layer of organic electroluminescence device.

The technical scheme that solution the utility model technical problem adopts is a kind of display unit, and it comprises above-mentioned array base palte.

Because display unit of the present utility model comprises above-mentioned array base palte, therefore its luminous efficiency obviously improves.

Accompanying drawing explanation

Fig. 1 is the schematic diagram of the surface plasma body resonant vibration of embodiment 1 metal micro-nano particle of the present utility model;

Fig. 2 is the metal micro-nano particle of the embodiment 1 of the present utility model schematic diagram to light scattering and absorption;

Fig. 3 is the structure chart of the array base palte of embodiment 1 of the present utility model;

Fig. 4 is the comparison diagram doped with the luminance of organic electroluminescence device in the array base palte of metal micro-nano particle and the luminance of the organic electroluminescence device in existing array base palte of the embodiment 1 of utility model;

Fig. 5 is the structure chart of the array base palte of embodiment 2 of the present utility model.

Wherein Reference numeral is: 101, substrate; 102, thin-film transistor; 103, planarization layer; 1031, the first planarization layer; 1032, the second planarization layer; 104, the first electrode layer; 105, pixel defines layer; 106, luminescent layer; 107, the second electrode lay; Q, metal micro-nano particle; The luminous efficiency curve of organic electroluminescence device in S1, existing array base palte; The luminous efficiency curve of organic electroluminescence device in S2, the utility model array base palte.

Embodiment

For making those skilled in the art understand better the technical solution of the utility model, below in conjunction with the drawings and specific embodiments, the utility model is described in further detail.

Embodiment 1:

In conjunction with Fig. 3, the present embodiment provides a kind of array base palte, it includes organic electroluminescence devices, organic electroluminescence device comprises: the first electrode layer 104, the second electrode lay 107, and be arranged on the luminescent layer 106 between the first electrode layer 104 and the second electrode lay 107, wherein, the first electrode layer 104 is transparent electrode layer, and it is arranged on the planarization layer 103 of doping metals micro-nano granules q.

In the planarization layer 103 of the transparent electrode layer below of the organic electroluminescence device of the array base palte of the present embodiment doped with metal micro-nano particle q, utilize the surface plasmon resonance effect of metal micro-nano particle q to strengthen the luminous efficiency of organic electroluminescence device, thereby strengthen the light emission rate of array base palte.

It should be noted that surface plasma (surface plasmons; SPs) refer to the electronics of the free vibration existing in metal surface and the electronics dilatational wave of propagating along metal surface that photon interacts and produces, electronics dilatational wave is a kind of electromagnetic surface wave, light wave laterally can be limited in the range scale of sub-wavelength, and approaching near its resonance frequency, its dispersion curve is smooth, Photon state density is large, during with active medium interaction, can strengthen surface plasma spontaneous radiation.Surface plasma is maximum in the surface of metallic film field intensity, perpendicular to interface direction, is being index collapsing field, and it can also can be excited by light wave by electronics.If the surface of metallic film is very coarse or near the curved-surface structure (as spheroid, cylinder etc.) of metal, its surperficial plasma can not be propagated along interface with the form of ripple, but by local the near surface in these structures, this is the localization of surface plasma.After metal micro-nano particle q that size approached or be less than optical wavelength is irradiated by light, its oscillating electric field makes the electron cloud of metal micro-nano particle q be subjected to displacement with respect to core, effect generation restoring force due between electron cloud and core coulomb of gravitation, cause that electron cloud is in core vibration around, the collective oscillation of this electron cloud is called as surface plasma body resonant vibration, as shown in Figure 1.

While there is surface plasma body resonant vibration, metal micro-nano particle q electromagnetic field is around strengthened greatly.Now metal micro-nano particle q can be thought to a nano lens, and vibration plasma be a photon, its by strong restrictions within the particle of a nano-scale.The very important effect that surface plasma body resonant vibration brings is exactly metal micro-nano particle q light scattering and absorption cross-section have all been strengthened greatly, as shown in Figure 2.

Wherein, the frequency of vibration is mainly determined by factors such as the size of the electron density (metal species) of metal micro-nano particle q, effective electron mass, particle, shape, surrounding mediums.The frequencies omega of surface plasma resonance _spcan obtain according to following formula:

$w_{\mathrm{sp}}=\frac{w_p}{\sqrt{1+2e_m}}$

Wherein, ω _pthe frequency of surface plasma, ε _mit is the dielectric constant of surrounding medium.

Organic light-emitting device external quantum efficiency (η _ext) can obtain according to the following formula:

${\mathrm{\η}}_{\mathrm{ext}}=C_{\mathrm{ext}}^{\′}\×{\mathrm{\η}}_{\mathrm{int}}=C_{\mathrm{ext}}^{\′}\×\frac{{\mathrm{\κ}}_{\mathrm{rad}}}{{\mathrm{\κ}}_{\mathrm{rad}}+{\mathrm{\κ}}_{\mathrm{non}}}$

C' wherein _extrepresent light extraction efficiency, h _intrepresent internal quantum efficiency.And internal quantum efficiency is by Radiation-induced deactivation speed (K _rad) and Nonradiative decay speed (K _non) ratio determine.In common room temperature situation, the Radiation-induced deactivation speed of organic electroluminescence device is faster than Nonradiative decay speed, causes a medium internal quantum efficiency h _int.Utilize surface plasma can improve respectively internal quantum efficiency and the light extraction efficiency of organic electroluminescence device.Wherein, the internal quantum efficiency that utilizes surface plasma to improve organic electroluminescence device is based on exciton spontaneous emission rate K _radthe principle relevant with the density of states, when luminescence center is in the microcavity of wavelength magnitude, the density of states of photon increases, and causes the increase of exciton spontaneous emission rate, thereby has improved the ratio of Radiation-induced deactivation, is also that internal quantum efficiency is improved.Utilize surface plasma improve illumination efficiency of organic electroluminescent device be based on be greater than alinternal reflection angle and the light that can not radiate can excitating surface stereoscopic plasma, it is radiate in the mode of light again, thereby improve the external quantum efficiency of organic electroluminescence device.This shows, rationally utilize the surface plasmon resonance effect of metal micro-nano particle q can effectively improve the external quantum efficiency of organic electroluminescence device.

In sum, the organic electroluminescence device transparent electrode layer of the array base palte that the present embodiment provides is located at planarization layer 103 tops doped with metal micro-nano particle q, so the luminous efficiency of the organic electroluminescence device in array base palte can improve greatly, improve the light emission rate of array base palte simultaneously.

Preferably, the material of metal micro-nano particle q can be gold, silver, aluminium, any one metal, or the alloy of various metals arbitrarily in gold, silver, aluminium.Can certainly adopt the composite construction of other metals.The form of metal micro-nano particle q be in spherical, prism-shaped, Fang Tizhuan, cage shape, nucleocapsid structure any one, its particle diameter is between 1nm-100nm, the grain size of different size, and the size of all metal micro-nano particle q particle diameters is preferably not identical, energy and the different wave length of the surface plasma of the metal micro-nano particle q of generation resonance are like this corresponding, thereby more effectively improve the luminous efficiency of organic electroluminescence device.

Preferably, the mass concentration ratio of metal micro-nano particle q and planarization layer 103 is controlled at and is more than or equal to 1% and be less than or equal to 5%, to guarantee can not to be subject to too large impact to the electric property of planarization layer 103.In planarization layer 103, the metal micro-nano particle q of doping can be that uniform doping also can make doping heterogeneous, such as embeds according to certain regular figure.

Wherein, the first electrode layer 104 is anode layer, and the second electrode lay 107 is cathode layer, or the first electrode layer 104 is cathode layer, and the second electrode lay 107 is anode layer.Can printing opacity as long as assurance is arranged on the planarization layer 103 of doping metals micro-nano granules q.Preferably, if the first electrode layer 104 is anode layer, its material be in tin indium oxide, zinc oxide, indium oxide gallium zinc any one.Now the second electrode lay 107 is reflector, cathode layer namely, and its material can be selected the metal materials such as silver, copper, aluminium; If the first electrode layer 104 is cathode layer, its material also can be chosen the metal materials such as silver, copper, aluminium, the very thin thickness of this layer now, to guarantee that light can see through the first electrode layer 104, now the second electrode lay 107 namely the exiting surface side of anode layer reflector is set, for example, the reflector that the reflective material such as aluminium, silver is made, when irradiation is during at the second electrode lay 107, by reflector, can reflex to the first electrode layer 104, and see through the first electrode layer 104.

Certainly on array base palte, also comprise thin-film transistor 102, the drain electrode of preferred film transistor 102 is connected by running through its top contact via hole of planarization layer 103 and the first electrode layer of organic electroluminescence device.Now by thin-film transistor 102, drive organic electroluminescence device luminous, make the light of organic electroluminescence device emit (namely end emission type organic electroluminescence device) through substrate 101.

As shown in Figure 4, X-direction is wavelength, Y-direction is luminous intensity, S1 is the luminous efficiency of organic electroluminescence device in the array base palte of existing planarization layer 103, S2 is the luminous efficiency doped with organic electroluminescence device in the array base palte of the planarization layer 103 of metal micro-nano particle q, is easy to draw that the luminous efficiency doped with organic electroluminescence device in the array base palte of the planarization layer 103 of metal micro-nano particle q obviously improves.

Embodiment 2:

The present embodiment provides a kind of display unit, it comprises the array base palte described in embodiment 1, and this display unit can be: any product or parts with Presentation Function such as mobile phone, panel computer, television set, display, notebook computer, DPF, navigator.

In the display unit of the present embodiment, have the array base palte in embodiment 1, therefore it has better luminous efficiency, visual effect is better.

Certainly, in the display unit of the present embodiment, can also comprise other conventional structures, as power subsystem, display driver unit etc.

Embodiment 3:

The present embodiment provides a kind of preparation method of array base palte, and it comprises the steps:

Step 1, in substrate 101, by composition technique, form thin-film transistor 102.Wherein, thin-film transistor 102 can be also bottom gate type for top gate type.

Certainly, also can form gate line, data wire etc., thin-film transistor drives and can be 2T1C etc. simultaneously.

Step 2, in the substrate 101 that is formed with thin-film transistor 102, form the planarization layer 103 doped with metal micro-nano particle q.

Wherein, the planarization layer 103 of preparing doping metals micro-nano granules q can be adopted with the following method;

Method one, structural representation as shown in Figure 5, in the film crystal substrate 101 of making, first deposit the first planarization layer 1031, then adopts in its surface the mode of sputter to plate the gold layer that one deck 2nm is thick, is then placed on vacuum degree and is less than 1x10 ^-3under the vacuum environment of Pa, with the annealing temperatures of 300 ℃, after half an hour, be chilled to room temperature, form discrete metal micro-nano particle q layer.And then deposit the second planarization layer 1032 thereon with electron beam evaporation or vapour deposition mode, with covering metal micro-nano granules layer, obtaining the planarization layer 103(that inside is embedded with metal micro-nano particle q consists of jointly the first planarization layer 1031, the second planarization layer 1032, metal micro-nano stratum granulosum), as shown in Figure 5.Wherein, the sputtering method adopting in above-mentioned manufacturing process also can replace with other dry-film technology, such as: vacuum evaporation, chemical vapour deposition technique etc.

The method of method two, employing sputter, the technical process of the flatness layer of formation doping metals micro-nano granules q.Its detailed process is as follows:

Adopt multi-target magnetic control sputtering technology to prepare gold (Au) and the silicon dioxide (SiO of metal micro-nano particle q dispersal oxide ₂) laminated film.In the magnetron sputtering cavity of two targets, a target is placed high-purity silicon dioxide, places high-purity gold for one.Sputter gas is high-purity argon (99.995%).Before sputter, the vacuum degree of cavity is <5 * 10 ^-5pa, sputtering pressure is 1.6 * 10 ^-1pa.During sputter, the flow of argon gas and oxygen is respectively 8.3 * 10 ^-8m ³/ s and 5.8 * 10 ^-8m ³/ s, silicon dioxide and golden radio-frequency power are respectively 200W and 50W.By opening the adjustable shutter before sputtering target, select to deposit to the ratio of material in substrate 101, thereby gold (metal receive the micron particles)-silicon dioxide laminated film that obtains different doping ratios, finally obtains the planarization layer 103 that Uniform Doped has metal micro-nano particle q.

Method three, take doped with silver (Ag) be core, with silicon dioxide (SiO ₂) be nucleocapsid structure (the Ag@SiO of shell ₂) the planarization layer 103 of metal micro-nano particle q be example, the detailed process of its making is as follows:

The metal micro-nano particle q of preparation Ag@SiO2, concrete steps comprise:

First hydrazine hydrate and silver nitrate are all made into weak solution; Taking 72.89mg softex kw (CTAB) is dissolved in 200mL deionized water, add 2.5mL concentration is the hydrazine hydrate of 0.1M simultaneously, utilize magnetic stirring apparatus at room temperature to stir, after about 2 minutes, dropwise adding 5mL concentration is the silver nitrate of 0.05M, solution colour gradually becomes rufous from water white transparency, within sustained response 7-10 minute, obtains nano silver colloid; Add subsequently the ammoniacal liquor that 50mL absolute ethyl alcohol and 2mL mass concentration are 25%, after about 1 minute, dropwise add 0.25mLTEOS, continue to stir 2 hours, obtain monodispersed nuclear shell structured nano-Ag@SiO ₂colloid aqueous solution.

Take sol-gel process preparation doped with the planarization layer 103 of metal micro-nano particle q, concrete steps comprise:

By the Ag@SiO of above-mentioned preparation ₂be dispersed in the mixed solution of tetraethoxysilane, absolute ethyl alcohol, watery hydrochloric acid composition, at room temperature form silicon dioxide gel.Take subsequently the method for spin coating, prepare planarization layer 103, be drying to obtain and be embedded with Au@SiO ₂the silica membrane of particle, namely doped with the planarization layer 103 of metal micro-nano particle q.

The planarization layer 103 of take again doped with the nucleocapsid structure of Au@polystyrene is example, specifically comprises:

The preparation of the nucleocapsid structure of Au@polystyrene, concrete steps are as follows:

Get 1.0g nano-gold powder, 1.0g PVP adds in 80mL water, then utilize supersonic generator continuous ultrasound to disperse 0.5h (the power 500W of supersonic generator), the emulsifying agent that adds again 1.0g, utilizes supersonic generator continuous ultrasound to disperse 0.5h to obtain dispersed system; Afterwards, transfer them to electric mixer, serpentine condenser, N are housed ₂in the four-hole boiling flask of pipe.Said apparatus is placed in to Water Tank with Temp.-controlled, maintains stir about l0min, be cooled to 30 ℃ to avoid excess Temperature to cause KPS to add rear premature decomposition; Add initiator potassium persulfate (KPS), maintain and stir 20min, therebetween logical N ₂row O ₂; Then, the styrene monomer after purifying is placed in to dropping funel and dropwise adds reaction system, about l0min drips off; Then, be warming up to 70 ℃, stir speed (S.S.) and logical N in course of reaction ₂it is constant that speed keeps.After 5h, finish reaction and under stirring, be naturally cooled to 40 ℃ with bottom discharge, obtain compounded latex.By a certain amount of for compounded latex after sodium chloride (NaCl) breakdown of emulsion, filter, washing, dry, obtain take gold nano grain as core, the nucleocapsid structure that polystyrene is shell.

Formation, doped with the planarization layer 103 of the nucleocapsid structure of Au@polystyrene, specifically comprises:

The nucleocapsid structure of the above-mentioned Au@polystyrene of making is dispersed in organic solvent, then mix with the photoresist (such as polyimide solution) of preparation formation flatness layer, take to obtain photoresist film such as the technique of spin coating, after being dried, be the planarization layer 103 doped with metal micro-nano particle q.

Step 3, the first electrode layer 104, the pixel that above the planarization layer 103 doped with metal micro-nano particle q of being made by said method, are formed with successively organic electroluminescence devices define layer 105, luminescent layer 106, the second electrode lay 107.The final array base palte that forms.

Doping metals micro-nano granules q in the planarization layer 103 of array base palte prepared by employing said method, it can effectively improve the light extraction efficiency of organic electroluminescence device, thereby improves the light emission rate of array base palte.

Be understandable that, above execution mode is only used to principle of the present utility model is described and the illustrative embodiments that adopts, yet the utility model is not limited to this.For those skilled in the art, in the situation that not departing from spirit of the present utility model and essence, can make various modification and improvement, these modification and improvement are also considered as protection range of the present utility model.

Claims (7)

1. an array base palte, include organic electroluminescence devices, described organic electroluminescence device comprises: the first electrode layer, the second electrode lay and be arranged on the luminescent layer between the first electrode layer and the second electrode lay, it is characterized in that, described the first electrode layer is transparent electrode layer, and it is arranged on the planarization layer of doping metals micro-nano granules.

2. array base palte according to claim 1, is characterized in that, described metal micro-nano granular materials be in gold, silver, aluminium any one.

3. array base palte according to claim 1, is characterized in that, the form of described metal micro-nano particle be in spherical, prism-shaped, cubic, nucleocapsid structure any one.

4. array base palte according to claim 1, is characterized in that, the particle diameter of described metal micro-nano particle is between 1nm-100nm.

5. array base palte according to claim 1, is characterized in that, described the first electrode layer is anode layer, its material be in tin indium oxide, zinc oxide, indium oxide gallium zinc any one.

6. array base palte according to claim 5, is characterized in that, also comprises thin-film transistor,

The drain electrode of described thin-film transistor is connected by running through its top contact via hole of planarization layer and the first electrode layer of organic electroluminescence device.

7. a display unit, is characterized in that, comprises the array base palte described in any one in claim 1～6.

Images