CN104795510A - Ultralow-voltage OLED device based on Auger electron injection - Google Patents
Ultralow-voltage OLED device based on Auger electron injection Download PDFInfo
- Publication number
- CN104795510A CN104795510A CN201410755249.3A CN201410755249A CN104795510A CN 104795510 A CN104795510 A CN 104795510A CN 201410755249 A CN201410755249 A CN 201410755249A CN 104795510 A CN104795510 A CN 104795510A
- Authority
- CN
- China
- Prior art keywords
- layer
- electron
- auger electrons
- auger
- oled
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Abstract
The invention provides an ultralow-voltage OLED device based on Auger electron injection and a preparation technical method thereof. The device comprises a substrate, an anode, a hole injection layer, a hole transport layer, a light emitting layer, an Auger electron generation layer, an electron transport layer, an electron injection layer, and a cathode, wherein the Auger electron generation layer is composed of an electron acceptor layer and an electron donor layer. According to the device, auger recombination of electrons and holes occurs on the interface of the electron acceptor layer or the electron donor layer in the Auger electron generation layer, which provides internal energy for electrons and greatly reduces the opening voltage of the device. The opening voltage of the ultralow-voltage OLED device based on Auger electron injection provided by the invention is lower than the band gap of a light emitting material.
Description
Technical field
The present invention relates to organic semiconductor device field, particularly relate to a kind of extra low voltage Organic Light Emitting Diode (OLED) device and technology of preparation method thereof.
Background technology
Organic Light Emitting Diode (OLED) is just becoming the mainstream technology of the ubiquitous electronic product display screen curtain such as TV, smart mobile phone, panel computer, because OLED has, driving voltage is low, efficiency is high, luminous visual angle is wide, fast response time; Ultra-thin, lightweight, all solidstate active illuminating; Flexible, can on a large scale, the advantage such as large area production.In addition, OLED also receives at lighting field and studies widely, is considered to the solid-state illumination light source of future generation of alternative fluorescent lamp and inorganic LED.
Determine electroluminescence (EL) performance of the principal element OLED of OLED large-scale commercial application.Early stage anthracene crystal OLED (J. Chem. Phys., the 38th volume, 2042(1963)) do not have actual property to apply, be because it is greater than the driving voltage of 100 V.The people such as the Deng Qingyun of Kodak in 1987 report double-deck OLED structure (Appl. Phys. Lett., 51st volume, 913(1987)), owing to containing hole injection/transport layer and electron injection/transport layer in device architecture simultaneously, greatly reduce the driving voltage (being less than 10 V) of device, and make OLED technology enter a practical stage.
OLED is that single or multiple lift organic active layer is embedded between two electrodes, wherein electronics and hole are injected from negative electrode and anode to the organic active layer between electrode respectively, and it is close owing to transporting in opposite directions under electric field action, and then exciton is produced in organic layer, final exciton produces light radiation through radiation transistion.Therefore, from theory, the applied voltage of driving OLED devices function at least should be not less than the band gap (or energy of emitted photons) of luminescent material.
In the past few decades, in order to reduce the driving voltage of OLED, people have made a lot of effort, comprise the performance to improving organic material, improve the design of device architecture, introduce PEDOT:PSS, HAT-CN, C
60, MoO
3, WO
3and V-
2o
5modify at resilient coating antianode interface, and increase LiF, Liq, Libpp and Cs between organic layer and negative electrode
2cO
3the injection efficiency of electronics is strengthened Deng electron injecting layer.Based on these effort, the cut-in voltage of the OLED in current many reports is all close to the band gap of luminescent material.
But this does not also mean that the improvement of the EL performance for OLED just stops at this, and OLED still has the potentiality further developed.
Summary of the invention
The object of the present invention is to provide a kind of new technical method, make the cut-in voltage of OLED can drop to below the band gap of luminescent material.
For reaching above-mentioned purpose, the present invention proposes a kind of auger electrons generating layer, and be made up of electron acceptor layer and electron donor layer, wherein electron donor material and electron acceptor material are high carrier mobility material.
In the auger electrons generating layer that the present invention proposes, electron acceptor layer/electron donor bed boundary has larger energy barrier, make electronics and hole at interface aggregates, and there is the non-radiative auger recombination of electron-hole, the energy that this recombination process produces is delivered to another electronics, makes this electron transition become auger electrons to high level.
For reaching above-mentioned purpose, the present invention proposes a kind of extra low voltage OLED injected based on auger electrons, be made up of substrate, anode, hole injection layer, hole transmission layer, luminescent layer, auger electrons generating layer, electron transfer layer, electron injecting layer, negative electrode, it is characterized in that between luminescent layer and electron transfer layer, be provided with auger electrons generating layer.
The extra low voltage OLED injected based on auger electrons that the present invention proposes, because auger recombination process is that auger electrons provides internal energy, thus reduce the applied external potential energy that this electron institute need overcome potential barrier, the cut-in voltage of device is obtained and significantly reduces.
Accompanying drawing explanation
Fig. 1 represents auger electrons generating layer of the present invention and auger electrons generation mechanism schematic diagram;
Fig. 2 represents the structural representation of the extra low voltage OLED based on auger electrons injection of the present invention, numeral wherein: 1, substrate; 2, anode; 3, hole injection layer; 4, hole transmission layer; 5, luminescent layer; 6, auger electrons generating layer; 7, electron transfer layer; 8, electron injecting layer; 9, negative electrode;
Fig. 3 represents the fundamental diagram of the extra low voltage OLED based on auger electrons injection of the present invention;
Fig. 4 represents current-voltage, the luminance-voltage relation curve of OLED in embodiment 1;
Fig. 5 represents OLED electroluminescent spectrum figure at different brightnesses in embodiment 1;
Fig. 6 represents the luminance-voltage relation curve of OLED in embodiment 2;
Fig. 7 represents the electroluminescent spectrum figure of OLED in embodiment 2.
Embodiment
In order to make above-mentioned purpose of the present invention, feature and advantage can be more clear understandable, shown in accompanying drawing, be described below in detail.
The auger electrons generating layer that the present invention proposes, is made up of electron acceptor layer and electron donor layer.Described electron acceptor material and electron donor material are high carrier mobility material, wherein electron acceptor material is except possessing high hole mobility, also need that there is narrower band gap, the material with polycyclic aromatic structure can be adopted, as 5,6,11,12-tetraphenyl aphthacene (Rubrene), pentacene (Pentacene) or aphthacene (Tetracene) etc., or adopt metal complex materials, as three (1-phenyl-isoquinolin) close iridium [Ir (piq)
3], two (1-phenyl-isoquinolin) (acetylacetone,2,4-pentanediones) close iridium [Ir (piq)
2(acac)], three (2-phenylpyridines) close iridium [Ir (ppy)
3], acetopyruvic acid two (2-phenylpyridine) iridium [Ir (ppy)
2(acac)] or two (4,6-difluorophenyl pyridinato-N, C2) pyridinecarboxylic close iridium (FIrpic) etc.; Electron donor material, except possessing high electron mobility, also needs to have and darker does not minimumly occupy track (LUMO) energy level, can adopt B4PyPPM, 3,4,9,10-perylene 4 formyl-2-imide (PTCDI), 3,4,9,10-tetracarboxylic anhydride (PTCDA), fullerene (C
60) and fullerene derivate (C
70or PCBM) etc.
With reference to Fig. 1, in the auger electrons generating layer that the present invention proposes, because electron acceptor layer/electron donor bed boundary has larger energy barrier, make electronics and hole at interface aggregates, thus radiationless auger recombination occurs, and the energy (E=L that compound produces
d-H
a) pass to the another one electronics on body lumo energy, and make this electron transition to high level.This electronics is called auger electrons.Under electric field action, this electronics can be directly injected into the lumo energy of acceptor material.Therefore, by auger recombination mechanism, electronics is made to transit to the effect of lumo energy without any need for external voltage of acceptor material from the lumo energy of donor material.
With reference to Fig. 2, the extra low voltage OLED injected based on auger electrons that the present invention proposes, each layer arranges according to following order from the bottom up: substrate 1, anode 2, hole injection layer 3, hole transmission layer 4, luminescent layer 5, auger electrons generating layer 6, electron transfer layer 7, electron injecting layer 8, negative electrode 9, it is characterized in that between luminescent layer and electron transfer layer, be provided with auger electrons generating layer as above.
In practical devices design, in order to reduce injection barrier, electron transport layer materials is usually consistent with the electron donor material of auger electrons generating layer.Namely electron transfer layer takes on the effect of the electron donor in electric transmission and auger electrons generating layer simultaneously, and auger electrons generating layer only includes electron acceptor material.Even, when the electron acceptor material in auger electrons generating layer has luminescent properties simultaneously, electron acceptor material can simultaneously as luminescent layer and hole transmission layer, and the electron acceptor layer now in hole transmission layer, luminescent layer and auger electrons generating layer is same layer.
With reference to Fig. 3, the OLED injected based on auger electrons that the present invention proposes, the operation principle realizing extra low voltage is: 1. in auger electrons generating layer/electric transmission bed boundary, auger recombination occurs by two end electrodes injected electrons and hole, and produce auger electrons; 2. auger electrons is under electric field action, is injected into the lumo energy of auger electrons generating layer; 3. auger electrons is injected into the lumo energy of luminescent layer further; There is radiation recombination and make device luminous in the hole 4. on auger electrons and luminescent layer HOMO energy level.
It is to be noted that in order to graphic simplicity, do not indicate hole injection layer and electron injecting layer in figure 3, and in the figure, auger electrons generating layer only comprises electron acceptor layer, and electron donor layer is directly served as by electron transfer layer.
The extra low voltage OLED injected based on auger electrons that the present invention proposes, because auger recombination is that electronics provides L
a-L
dinternal energy, and make the external voltage needed for OLED luminescence reduce L
a-L
d, thus achieve the object reducing OLED cut-in voltage.
The extra low voltage OLED injected based on auger electrons that the present invention proposes, the effect of auger electrons generating layer is the interface of a creation electron-hole generation auger recombination, produces auger electrons.In order to enable auger electrons effectively be injected into luminescent layer, the thickness of auger electrons generating layer is unsuitable blocked up, and preferred thickness is 3 ~ 5 nm.
The extra low voltage OLED injected based on auger electrons that the present invention proposes, except being provided with auger electrons generating layer described above between luminescent layer and electron transfer layer, all the other are the conventional components in OLED.
Described substrate 1 can be common smooth glass, sapphire or silicon chip etc.
Described anode 2 can adopt aluminium (Al), silver (Ag), platinum (Pt), gold (Au) or photoetching tin indium oxide (ITO).
Described hole injection layer material, can adopt poly-(3,4-Ethylenedioxy Thiophene)-gather (styrene sulfonic acid) (PEDOT:PSS), 2,3,6,7,10,11-, six cyano group-Isosorbide-5-Nitrae, 5,8,9,12-six azepine benzophenanthrene (HAT-CN), fullerene (C-
60) or molybdenum trioxide (MoO
3), tungstic acid (WO
3), vanadic oxide (V
2o
5) etc. metal oxide.For the hole transport layer material that hole injection barrier is lower, also hole injection layer can not be used.
Described hole transport layer material, following hole mobile material can be adopted: 4, 4', 4''-tri-(N-3-methylphenyl-N-phenyl is amino) triphenylamine (m-MTDATA), N, N'-diphenyl-N, N'-(1-naphthyl)-1, 1'-biphenyl-4, 4'-diamines (NPB), 4-[1-[4-[two (4-aminomethyl phenyl) is amino] phenyl] cyclohexyl]-N-(3-aminomethyl phenyl)-N-(4-aminomethyl phenyl) aniline (TAPC), 4, 4', 4''-tri-(carbazole-9-base) triphenylamine (TCTA), or 4, 4'-bis-(9-carbazole) biphenyl (CBP) etc.But in order to not increase extra voltage loads, hole transport layer material should be selected according to luminescent material, namely the HOMO energy level of hole transport layer material should be more shallow than the HOMO energy level of emitting layer material.
Described emitting layer material, can adopt in following luminescent material one or more: (E)-4-dintrile methylene-2-tert-butyl group-6-(1,1,7,7-tetramethyl julolidine vinyl) pyrans (DCJTB), 2,3,6,7-tetrahydrochysene-1,1,7,7-tetramethyl-1H, 5H, 11H-10-(2-[4-morpholinodithio base)-quinolizino [9,9A, 1GH] cumarin (C545T), oxine aluminium (Alq
3), two (2-hydroxy phenyl pyridines) close beryllium (BePP
2), three (1-phenyl-isoquinolin) close iridium [Ir (piq)
3], two (1-phenyl-isoquinolin) (acetylacetone,2,4-pentanediones) close iridium [Ir (piq)
2(acac)], three (2-phenylpyridines) close iridium [Ir (ppy)
3], acetopyruvic acid two (2-phenylpyridine) iridium [Ir (ppy)
2(acac)] or two (4,6-difluorophenyl pyridinato-N, C2) pyridinecarboxylic close iridium (FIrpic) etc.
Above-mentioned luminescent layer both can adopt separately above-mentioned luminescent material to obtain as luminescent layer, or two or more luminescent material with energy transfer mechanism can be adopted to adulterate and obtain.
For the ease of the injection of auger electrons, above-mentioned emitting layer material should material that preferably lumo energy is darker, or the material that lumo energy comparatively mates with the lumo energy of electron acceptor material in auger electrons generating layer.
Because hole through luminescent layer, will be transferred to auger electrons generating layer, for the emitting layer material that hole mobility is lower, its thickness is unsuitable blocked up, and preferred thickness is 5 ~ 10 nm.
Described electron transport layer materials, preferably simultaneously as the material of the electron donor of auger electrons generating layer, can adopt B4PyPPM, 3,4,9,10-perylene 4 formyl-2-imides (PTCDI), 3,4,9,10-tetracarboxylic anhydrides (PTCDA), fullerene (C
60) and fullerene derivate (C
70or PCBM) etc.
Described electron injecting layer material, bromocresol purple sodium salt (BCP), lithium fluoride (LiF), oxine-lithium (Liq) or 2-(2' can be adopted, 2''-bipyridine-6'-base)-phenylol conjunction lithium (Libpp) etc., when wherein adopting BCP, preferred thickness is 7 nm, when adopting LiF, Liq or Libpp, preferred thickness is 1 nm.
Described negative electrode can adopt Al, Ag, magnesium (Mg) or calcium (Ca) etc., is preferably Al, is preferably Ag for top emitting device for bottom emitting device.
Below, by specific embodiment, the present invention will be described in more detail.
Embodiment 1: a kind of OLED injected based on auger electrons, this device layers arranges according to following order from the bottom up: substrate 1, anode 2, hole transmission layer 4, luminescent layer 5, auger electrons generating layer 6, electron transfer layer 7, electron injecting layer 8, negative electrode 9, wherein:
Substrate 1 is level and smooth, the good glass of light transmission;
Anode 2 is photoetching ITO on the base 1, and resistance is 15 Ω/sq;
Hole transmission layer 4 is for being deposited on the NPB on anode 2, and thickness is 20 nm;
Luminescent layer 5 is for being deposited on the doped luminescent material Alq on hole transmission layer 4
3: DCJTB, doping content is 1 wt.%, and thickness is 5 nm;
Auger electrons generating layer 6 is for being deposited on the Rubrene on 5, and thickness is 5 nm;
Electron transfer layer 7 is for being deposited on the C on 6
60, thickness is 20 nm;
Electron injecting layer 8 is for being deposited on the BCP on 7, and thickness is 7 nm;
Negative electrode 9 is for being deposited on the Al on 8, and thickness is 100 nm.
Fig. 4 and Fig. 5 sets forth the electroluminescent spectrum under the luminance-voltage of OLED injected based on auger electrons of embodiment 1, current-voltage relation curve and different brightness.As can be seen from Figure 4, the cut-in voltage of device is 1.5 V, and as can be seen from Figure 5, the luminous photon energy of device is 2.0 eV (620 nm), shows that the cut-in voltage of this device obtains low 0.5 V of band gap than luminescent material DCJTB.
Embodiment 2: a kind of OLED injected based on auger electrons, this device layers arranges according to following order from the bottom up: substrate 1, anode 2, hole transmission layer 4, luminescent layer 5, auger electrons generating layer 6, electron transfer layer 7, electron injecting layer 8, negative electrode 9, wherein:
Substrate 1 is level and smooth, the good glass of light transmission;
Anode 2 is photoetching ITO on the base 1, and resistance is 15 Ω/sq;
Hole injection layer 3 is for being deposited on the MoO on 2
3, thickness is 1nm;
Electron acceptor layer material in hole transmission layer 4, luminescent layer 5 and auger electrons generating layer 6 is commaterial, is same layer, and material is Ir (piq)
2(acac), Ir (ppy)
3or FIrpic, thickness is 30 nm;
Electron donor layer material in auger electrons generating layer 6 and electron transfer layer 7 material are commaterial, are same layer, and material is B4PyPPM, and thickness is 20nm;
Electron injecting layer 8 is for being deposited on the LiF on 7, and thickness is 1 nm;
Negative electrode 9 is for being deposited on the Al on 8, and thickness is 100 nm.
Fig. 6 and 7 sets forth luminance-voltage relation curve and the electroluminescence luminous spectrum of three kinds of basic colors OLED in embodiment 2.Table 1 lists the result of OLED in embodiment 1 and 2:
Table 1
。
From table 1, by the introducing of auger electrons generating layer, producing auger electrons, and utilize the injection of auger electrons, is the effective technology method realizing extra low voltage OLED.
Although the present invention with the embodiment of practicality to invention has been above description, so itself and be not used to limit the present invention.Should be appreciated that the present invention should not be limited to disclosed example embodiment, on the contrary, any amendment made within all spirit not departing from claims of the present invention and principle, equivalently to replace and improvement etc., all should be included within protection scope of the present invention.
Claims (6)
1. an auger electrons generating layer, be made up of electron acceptor layer and electron donor layer, it is characterized in that electron acceptor layer is made up of the material possessing high hole mobility and narrow band gap, electron donor layer is by possessing high electron mobility and the minimum material not occupying orbital energy level is formed.
2. auger electrons generating layer as claimed in claim 1, wherein said electron acceptor layer material is the wherein one of Rubrene, pentacene, aphthacene.
3. auger electrons generating layer as claimed in claim 1, wherein said electron donor layer material is the wherein one of fullerene, fullerene derivate, 3,4,9,10-perylene 4 formyl-2-imides, B4PyPPM.
4. auger electrons generating layer as claimed in claim 1, is characterized in that the thickness of described auger electrons generating layer is 3 ~ 5nm.
5. the extra low voltage OLED injected based on auger electrons, be made up of substrate, anode, hole injection layer, hole transmission layer, luminescent layer, auger electrons generating layer, electron transfer layer, electron injecting layer, negative electrode, it is characterized in that between luminescent layer and electron transfer layer, be provided with auger electrons generating layer as claimed in claim 1.
6., as claimed in claim 5 based on the extra low voltage OLED that auger electrons injects, it is characterized in that the band gap of cut-in voltage lower than luminescent material of this device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410755249.3A CN104795510B (en) | 2014-12-11 | 2014-12-11 | The ultra low voltage OLED injected based on auger electrons |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410755249.3A CN104795510B (en) | 2014-12-11 | 2014-12-11 | The ultra low voltage OLED injected based on auger electrons |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104795510A true CN104795510A (en) | 2015-07-22 |
| CN104795510B CN104795510B (en) | 2017-08-25 |
Family
ID=53560176
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410755249.3A Active CN104795510B (en) | 2014-12-11 | 2014-12-11 | The ultra low voltage OLED injected based on auger electrons |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104795510B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100207114A1 (en) * | 2007-10-31 | 2010-08-19 | Basf Se | Use of halogenated phthalocyanines |
| CN103606633A (en) * | 2013-11-28 | 2014-02-26 | 电子科技大学 | Organic electroluminescence and photovoltaic integration device and manufacturing method |
-
2014
- 2014-12-11 CN CN201410755249.3A patent/CN104795510B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100207114A1 (en) * | 2007-10-31 | 2010-08-19 | Basf Se | Use of halogenated phthalocyanines |
| CN103606633A (en) * | 2013-11-28 | 2014-02-26 | 电子科技大学 | Organic electroluminescence and photovoltaic integration device and manufacturing method |
Non-Patent Citations (1)
| Title |
|---|
| AJAY K.PANDEY等: "Rubrene/fullerene heterostructures with half-gap electroluminescence threshold and large photovoltage", 《ADVANCED MATERIALS》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104795510B (en) | 2017-08-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI570985B (en) | An organic electroluminescent display device having an RGB pixel region | |
| CN101447555B (en) | Laminated organic electro-luminescent device of an organic semiconductor-based hetero-junction electric-charge generating layer taken as a connecting layer and preparation method thereof | |
| CN102169966B (en) | Organic light emitting diode | |
| CN102694131B (en) | Organic light-emitting device, manufacturing method thereof and display device | |
| CN105304828B (en) | A kind of Tandem white organic luminescent device | |
| CN102651451B (en) | Electroluminescence device | |
| KR20180074761A (en) | Phosphorescent organic electroluminescent device | |
| CN102074658B (en) | Electric charge production layer, lamination layer organic light-emitting diode and preparation method thereof | |
| KR102605293B1 (en) | Organic light emitting diode and organic light emitting device having the diode | |
| CN105514291A (en) | Organic light-emitting device | |
| CN103490017B (en) | A kind of hydridization white light organic electroluminescent device | |
| Jou et al. | Efficient, color-stable fluorescent white organic light-emitting diodes with an effective exciton-confining device architecture | |
| CN102130302A (en) | Laminated organic light emitting diode and preparation method thereof | |
| CN104282839A (en) | Organic electroluminescent device, preparation method of organic electroluminescent device and display device | |
| Wang et al. | An efficient CsPbBr3 perovskite light-emitting diode by employing 1, 3, 5-tri (m-pyrid-3-yl-phenyl) benzene as a hole and exciton blocking layer | |
| CN101859879A (en) | White organic electroluminescent device and preparation method thereof | |
| Yadav et al. | Recent advancements over a decade for organic light-emitting diodes: from structural diversity, role of layers, colour emission, material classification, performance improvement, fabrication to applications | |
| CN109428005A (en) | Organic electroluminescence device | |
| KR102230925B1 (en) | Organic light emitting device | |
| EP2787792A1 (en) | Polymeric electroluminescent device and method for preparing same | |
| CN104638162A (en) | Organic electroluminescent device and production method thereof | |
| CN104638115A (en) | Organic light-emitting device and preparation method thereof | |
| Liu et al. | Angle-stable inverted top-emitting white organic light-emitting devices based on gradient-doping electron injection interlayer | |
| Ahn et al. | Solid state solvation effect of a donor–acceptor type fluorescent molecule and its application to white organic light-emitting diodes | |
| CN110165065B (en) | High-efficiency/color quality/color stability laminated white organic light-emitting diode |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| EXSB | Decision made by sipo to initiate substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |