CN111785846A - Green-light perovskite light-emitting diode based on surface post-treatment process and preparation - Google Patents
Green-light perovskite light-emitting diode based on surface post-treatment process and preparation Download PDFInfo
- Publication number
- CN111785846A CN111785846A CN202010507705.8A CN202010507705A CN111785846A CN 111785846 A CN111785846 A CN 111785846A CN 202010507705 A CN202010507705 A CN 202010507705A CN 111785846 A CN111785846 A CN 111785846A
- Authority
- CN
- China
- Prior art keywords
- perovskite
- layer
- light emitting
- transport layer
- green
- 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.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/80—Constructional details
- H10K50/84—Passivation; Containers; Encapsulations
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Electroluminescent Light Sources (AREA)
Abstract
A green perovskite light emitting diode based on a surface post-treatment process and a preparation method thereof belong to the field of semiconductor solid light emitting devices, and particularly relate to a surface passivation layer which takes butyl ammonium bromide as a perovskite light emitting layer and is used for perovskite light emitting diodes. The structure of the electrode comprises a transparent conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, an electrode modification layer and a metal aluminum electrode. Butyl ammonium bromide is modified on the perovskite light-emitting layer mainly by a spin coating method. The surface passivation layer improves the compactness of the perovskite layer, passivates the surface defects of the perovskite layer and effectively reduces the proportion of non-radiative recombination in the perovskite layer by inducing the perovskite recrystallization process. The starting voltage of the all-inorganic green-light perovskite light emitting diode integrated by the process is obviously reduced, the light emitting brightness and the light emitting efficiency are greatly improved, and the stability is obviously improved.
Description
Technical Field
The invention belongs to the field of perovskite light emitting diodes, and particularly relates to a green perovskite light emitting diode serving as a main body, a surface of a perovskite light emitting layer is coated with butyl ammonium bromide in a spin coating mode to serve as a surface passivation layer, and application of the surface passivation layer in a semiconductor light emitting device.
Technical Field
The Light Emitting Diode (LED) has the advantages of energy and electricity saving, environmental friendliness, small volume, quick response, long service life and the like, is widely applied to the fields of indication, display, backlight source, common illumination and the like, and particularly is the best choice for replacing incandescent bulbs in the aspect of energy and electricity saving. Common semiconductor light emitting materials in LED devices include inorganic light emitting materials, organic light emitting materials, quantum dot light emitting materials, and the like. The traditional inorganic luminescent material has the defects of low color purity, high energy consumption of a vacuum deposition preparation process and the like. Although solution processable Organic Light Emitting Diodes (OLEDs) and quantum dot light emitting diodes (QLEDs) have good light emitting properties, they are currently undergoing or just beginning to be commercialized, and have the disadvantages of short lifetime of blue OLEDs, high toxicity of chromium in QLEDs, low yield, high cost, and the like, which need to be overcome. The metal halide perovskite material as a direct band gap semiconductor material which can be prepared by a low-temperature solution process has the characteristics of continuously adjustable light-emitting wavelength, high light-emitting color purity and the like, and is considered as a powerful competitor of next-generation LED devices.
The perovskite material for manufacturing the LED has the structure of ABX3Wherein A ═ CH3NH3 +(MA),CH3(NH2)2 +(FA),Cs+；B＝Pb2+,Sn2+；X＝Cl-,Br-,I-. The current power conversion efficiency of light emitting diodes (pelds) based on perovskite materials has exceeded 20%, and despite the rapid development, there are still many fundamental problems with the current peld devices, both of which are the problems of the perovskite materials as the light emitting layer itself, the problems between the interfaces introduced when incorporating it into the device, or the problems existing when the device is operating, and it is therefore highly desirable to be addressed by researchers. The shape and quality of the perovskite luminescent layer directly determine the efficiency and stability of the PeLED device, but the perovskite thin film prepared by the solution method at present often has higher defect state density. Therefore, the development of a surface post-treatment process which can improve the appearance quality of the perovskite layer, can effectively passivate the defect state of the perovskite layer and balance electron and hole injection has important significance for manufacturing the efficient and stable perovskite light-emitting diode.
Disclosure of Invention
In order to solve the problems of the prior art, one of the objects of the present invention is to provide a surface post-treatment process.
The invention also aims to provide a green perovskite light emitting diode, and the LED device integration process comprises the surface post-treatment process.
The inventor researches and discovers that butyl ammonium bromide serving as a surface passivation layer is compounded on a perovskite luminous layer of a green perovskite luminous diode, so that the perovskite recrystallization process can be induced, the number of pinholes on the surface of a film is reduced, the compactness is improved, the defect states of a perovskite crystal boundary and the surface are passivated, the proportion of effective radiation recombination is improved, and the rate of injecting electrons and holes into a perovskite layer is balanced. The manufactured LED has the advantages of low starting voltage, high brightness and luminous efficiency, good stability and the like. The invention has simple manufacturing process, low cost and good repeatability and is suitable for manufacturing the light-emitting diode with large area.
The invention is realized by the following technical means:
a green perovskite light emitting diode based on a surface post-treatment process is characterized in that a device structure comprises an ITO transparent conductive substrate/a hole transport layer/(a perovskite layer + a surface passivation layer)/an electron transport layer/an electrode modification layer/an aluminum electrode which are sequentially stacked.
The conductive substrate is ITO conductive glass;
the hole transport layer is made of any one semiconductor material of TFB, PEDOT, PSS, CBP and PVK;
the material of the electron transport layer is any one semiconductor material of TPBi, F8, BCP and PCBM.
The perovskite luminescent layer has a chemical general formula of APbBr3Wherein A is one or more mixed cations in different proportions in cesium, methylamine and formamidine cations.
The perovskite layer and the surface passivation layer are formed by compounding the surface passivation layer on the perovskite layer.
The electrode modification layer is lithium fluoride (LiF).
The method for preparing the green perovskite light emitting diode based on the surface post-treatment process is characterized by comprising the following steps of:
1) preparation of hole transport layer:
the preparation method of the hole transport layer comprises the following steps: spin-coating the diluted hole transport layer dispersion liquid or solution on a clean ITO conductive substrate, and annealing to form a compact hole transport layer film;
the spin coating condition is 3000-5000 rpm, and the time is 1 min; the annealing condition is 150 ℃, and the time is 10-30 min;
2) preparation of perovskite layer + surface passivation layer:
according to the general chemical formula APbBr3The molar ratio of the elements in the raw materials is mixed, and corresponding amounts of ABr and PbB are weighed2Dissolving the precursor solution in one or two mixed solvents of dimethyl sulfoxide (DMSO) or N, N-Dimethylformamide (DMF) to obtain a precursor solution; firstly, spin-coating a precursor solution on the film obtained in the step 1) and annealing; the spin coating condition is 1500-3000 rpm, and the time is 2 min; the annealing condition is 80-120 ℃, and the time is 10-20 min; secondly, spin-coating a butyl ammonium bromide solution on the surface, and annealing to obtain a perovskite thin film with a passivated surface; the spin coating condition is 2000-4000 rpm, and the time is 30-60 s; the annealing condition is 80-100 ℃ and the time is 5-10 min.
Further preferably, the concentration of the precursor solution is 0.2-0.4M, and the concentration of the butyl ammonium bromide solution is 1-9 mg/mL.
3) Preparation of an electron transport layer:
the preparation method of the electron transport layer comprises the following steps: depositing an electron transport layer on the film in step 2) by vacuum evaporation, the evaporation rate being maintained at
And the thickness is 30-50 nm.
4) Preparing an electrode modification layer/aluminum electrode:
the preparation method of the electrode modification layer/aluminum electrode comprises the following steps: sequentially depositing the electrode modification layer and the aluminum electrode on the film in the step 3) by vacuum evaporation at the evaporation rates of
And
the thicknesses are respectively 1nm and 60-100 nm.
In the evaporation process of the steps 3 and 4), the pressure in the evaporation bin is less than 3.7 × 10-6Torr, evaporation can be started, and the evaporation rate is kept stable.
The first step of the solution spin-coating method in the step 2) is an anti-solvent one-step film forming method, the anti-solvent dripping method is that the anti-solvent is dripped at a constant speed from the positive number of 30-35 s after spin-coating, and the dripping time is 1-3 s; the antisolvent is one or more of chlorobenzene, toluene, ethyl acetate and diethyl ether, and the dripping amount is 4cm per time2The area is dripped with 150-200 mu l.
The method for the green-light perovskite light emitting diode based on the surface post-treatment process can efficiently and stably emit bright green light under the working voltage of 3.5-6.5V. The LED fluorescent lamp can be applied to the fields of display and illumination such as traffic signal lamps, mobile phone display screens, holiday lamp ornaments and the like. And simultaneously, the ultraviolet light is adopted for excitation, and bright green light can be emitted.
Compared with the prior art, the invention has the following advantages:
1) the green perovskite light emitting diode based on the surface post-treatment process has the advantages of simple preparation process, low cost and good repeatability.
2) The green perovskite light emitting diode based on the surface post-treatment process has the advantages that the method for modifying the perovskite light emitting layer by taking the butyl ammonium bromide as the surface passivation layer is not reported in documents, and through experimental tests, the green perovskite light emitting diode has lower starting voltage, obtains higher light emitting brightness and light emitting efficiency, and realizes good stability.
Drawings
FIG. 1, scanning electron micrographs of perovskite layers before and after surface passivation of BABr prepared in example 1.
FIG. 2 photo photoluminescence of perovskite layer before and after surface passivation of BABr prepared in example 1.
FIG. 3 is a Luminince-V curve of a green perovskite light emitting diode before and after surface passivation of BABr prepared in example 1. Fig. 4, EQE-V curves of green perovskite light emitting diodes before and after BABr surface passivation prepared in example 1, and the inset is a photograph of the emission of the device under dark conditions.
Detailed Description
The invention is further illustrated by the following figures and examples, but is not limited to the following examples.
Example 1
1) Preparation of hole transport layer:
and diluting the purchased Al4083 PEDOT/PSS solution with deionized water according to the dilution ratio of 2:1 (volume ratio of PEDOT to PSS to deionized water), coating the solution on clean ITO conductive glass in a spin coating manner, and annealing at 150 ℃ for 15min to form a compact PEDOT/PSS film.
2) Preparation of perovskite layer:
adding cesium bromide and lead bromide into DMSO according to a molar ratio of 1:1 to prepare a perovskite precursor solution with the concentration of 0.2M. Stirring for 12h at normal temperature to obtain clear and transparent colorless perovskite precursor solution. In a nitrogen glove box, 70uL of precursor solution is taken and adopted by a one-step spin coating method, the rotating speed is 2000rpm, the time is 2min, 150 mu L of anti-solvent is dripped into the positive 30s, the obtained perovskite film is annealed for 20min at the temperature of 100 ℃ on a heating plate, and the perovskite film is cooled to the room temperature. Then spin-coating 7mg/mL butyl ammonium bromide solution (solvent is isopropanol) on the surface, rotating speed is 3000rpm, time is 40s, and annealing is carried out at 90 ℃ for 10min to obtain the perovskite thin film with passivated surface.
3) Preparation of an electron transport layer:
depositing an electron transport layer on the film in step 2) by vacuum evaporation, the evaporation rate being maintained at
The thickness was 40 nm.
4) Preparing an electrode modification layer/aluminum electrode:
depositing the lithium fluoride and the aluminum electrode which are electrode modification layers on the film in the step 3) through vacuum evaporation, wherein the evaporation rates are respectively
And
the thicknesses were 1nm and 80nm, respectively.
The manufactured perovskite light-emitting diode realizes stable and efficient electroluminescence within the working voltage of 3.5-6.5V, and is in a better level in the green perovskite light-emitting diode without additive modification at present.
From fig. 1, it can be seen that the growth condition of the perovskite thin film after the surface passivation of BABr obviously reduces the number of surface pinholes and obviously improves the coverage rate.
It can be seen from fig. 2 that under the condition of ultraviolet excitation, the perovskite thin film after BABr surface passivation emits bright green light, which indicates that the defect state density in the perovskite layer is significantly reduced, and the proportion occupied by effective radiative recombination is increased (the green light brightness of the block on the right side below is much higher than that of the block on the left side below).
From fig. 3, it can be seen that the light emitting performance of the green perovskite light emitting diode device with the BABr surface passivated is remarkably improved, the starting voltage of the device is reduced from 4.3V to 3.0V, which shows that the leakage current of the device during operation is reduced due to the improved compactness of the perovskite thin film; maximum luminance from 23cd/m2Increased to 3296cd/m2。
From fig. 4, it can be seen that the light emitting efficiency of the green perovskite light emitting diode device with the BABr surface passivated is remarkably improved, and the EQE is improved from 0.08% to 3.90%.
Meanwhile, the half-life period of the device luminescence is measured to be about 60s under the conditions of room temperature 25 ℃ and humidity of 35-40%.
Claims (10)
1. The butyl ammonium bromide is applied as a surface passivation layer to be compounded on a perovskite luminous layer of a green perovskite luminous diode.
2. The use of butylammonium bromide according to claim 1 to induce a recrystallization process of perovskite, to improve the morphological quality of perovskite thin films, to passivate surface defects, to increase the fraction of effective radiative recombination, and to balance the rate of injection of electrons and holes into perovskite layers.
3. A green perovskite light emitting diode based on a surface post-treatment process is characterized in that a device structure comprises an ITO transparent conductive substrate/a hole transport layer/(a perovskite layer + a surface passivation layer)/an electron transport layer/an electrode modification layer/an aluminum electrode which are sequentially stacked.
4. The green perovskite light emitting diode based on the surface post-treatment process as claimed in claim 3, wherein the conductive substrate is ITO conductive glass; the hole transport layer is made of any one semiconductor material of TFB, PEDOT, PSS, CBP and PVK; the material of the electron transport layer is any one semiconductor material of TPBi, F8, BCP and PCBM.
5. The green perovskite light emitting diode based on the surface post-treatment process as claimed in claim 3, wherein the perovskite light emitting layer has a chemical formula of APbBr3Wherein A is one or more mixed cations in different proportions in cesium, methylamine and formamidine cations.
6. A green perovskite light emitting diode based on a surface post-treatment process as claimed in claim 3 wherein the electrode modification layer is lithium fluoride (LiF).
7. The method for preparing the green perovskite light emitting diode based on the surface post-treatment process as claimed in any one of claims 3 to 6, which is characterized by comprising the following steps:
1) preparation of hole transport layer:
the preparation method of the hole transport layer comprises the following steps: spin-coating the diluted hole transport layer dispersion liquid or solution on a clean ITO conductive substrate, and annealing to form a compact hole transport layer film;
the spin coating condition is 3000-5000 rpm, and the time is 1 min; the annealing condition is 150 ℃, and the time is 10-30 min;
2) preparation of perovskite layer + surface passivation layer:
according to the general chemical formula APbBr3The molar ratio of the elements in the raw materials is mixed, and corresponding amounts of ABr and PbB are weighed2Dissolving the precursor solution in one or two mixed solvents of dimethyl sulfoxide (DMSO) or N, N-Dimethylformamide (DMF) to obtain a precursor solution; firstly, spin-coating a precursor solution on the film obtained in the step 1) and annealing; the annealing condition is 80-120 ℃, and the time is 10-20 min; secondly, spin-coating a butyl ammonium bromide solution on the surface, and annealing to obtain a perovskite thin film with a passivated surface; the annealing condition is 80-100 ℃, and the time is 5-10 min;
3) preparation of an electron transport layer:
the preparation method of the electron transport layer comprises the following steps: depositing an electron transport layer on the film in step 2) by vacuum evaporation, the evaporation rate being maintained at
The thickness is 30-50 nm;
4) preparing an electrode modification layer/aluminum electrode:
the preparation method of the electrode modification layer/aluminum electrode comprises the following steps: sequentially depositing the electrode modification layer and the aluminum electrode on the film in the step 3) by vacuum evaporation at the evaporation rates of
And
the thicknesses are respectively 1nm and 60-100 nm.
8. The method as claimed in claim 7, wherein the concentration of the precursor solution in step 2) is 0.2-0.4M, the concentration of the butyl ammonium bromide solution is 1-9 mg/mL, the first spin-coating condition in step 2) is 1500-3000 rpm for 2min, the second spin-coating condition is 2000-4000 rpm for 30-60 s, and the pressure in the evaporation chamber during the evaporation process in steps 3 and 4) is less than 3.7 × 10-6Torr, vapor deposition can be startedThe evaporation rate is kept constant.
9. The method according to claim 7, wherein the first step of the solution spin coating in the step 2) is an anti-solvent one-step film forming method, and the anti-solvent dropping method is that the anti-solvent is dropped at a constant speed from the positive number of 30-35 s after the spin coating, wherein the dropping time is 1-3 s; the antisolvent is one or more of chlorobenzene, toluene, ethyl acetate and diethyl ether, and the dripping amount is 4cm per time2The area is dripped with 150-200 mu l.
10. The application of the green perovskite light emitting diode based on the surface post-treatment process as claimed in any one of claims 3 to 6 is characterized in that the application is in the fields of display and illumination of traffic signal lamps, mobile phone display screens, holiday lamp ornaments and the like. And simultaneously, the ultraviolet light is adopted for excitation, and bright green light can be emitted.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010507705.8A CN111785846A (en) | 2020-06-05 | 2020-06-05 | Green-light perovskite light-emitting diode based on surface post-treatment process and preparation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010507705.8A CN111785846A (en) | 2020-06-05 | 2020-06-05 | Green-light perovskite light-emitting diode based on surface post-treatment process and preparation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111785846A true CN111785846A (en) | 2020-10-16 |
Family
ID=72753984
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010507705.8A Pending CN111785846A (en) | 2020-06-05 | 2020-06-05 | Green-light perovskite light-emitting diode based on surface post-treatment process and preparation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111785846A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113707649A (en) * | 2021-08-02 | 2021-11-26 | 浙江大学 | Application of light-emitting diode driven by sub-band gap voltage and optical coupling device |
| CN113823751A (en) * | 2021-09-02 | 2021-12-21 | 深圳大学 | Perovskite light emitting diode and preparation method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107910456A (en) * | 2017-11-08 | 2018-04-13 | 华侨大学 | A kind of preparation method for mixing perovskite thin film and its application in LED |
| CN110350105A (en) * | 2019-07-02 | 2019-10-18 | 南昌航空大学 | A kind of perovskite light emitting diode with quantum dots and preparation method thereof containing two-dimentional perovskite passivation layer |
| CN111192971A (en) * | 2020-01-10 | 2020-05-22 | 上海大学 | Low roll-off quasi-two-dimensional perovskite light-emitting diode and preparation method thereof |
-
2020
- 2020-06-05 CN CN202010507705.8A patent/CN111785846A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107910456A (en) * | 2017-11-08 | 2018-04-13 | 华侨大学 | A kind of preparation method for mixing perovskite thin film and its application in LED |
| CN110350105A (en) * | 2019-07-02 | 2019-10-18 | 南昌航空大学 | A kind of perovskite light emitting diode with quantum dots and preparation method thereof containing two-dimentional perovskite passivation layer |
| CN111192971A (en) * | 2020-01-10 | 2020-05-22 | 上海大学 | Low roll-off quasi-two-dimensional perovskite light-emitting diode and preparation method thereof |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113707649A (en) * | 2021-08-02 | 2021-11-26 | 浙江大学 | Application of light-emitting diode driven by sub-band gap voltage and optical coupling device |
| CN113823751A (en) * | 2021-09-02 | 2021-12-21 | 深圳大学 | Perovskite light emitting diode and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Dayneko et al. | Solution processed red organic light-emitting-diodes using an N-annulated perylene diimide fluorophore | |
| US11245076B2 (en) | Perovskite optoelectronic device, preparation method therefor and perovskite material | |
| WO2021103471A1 (en) | Self-assembling multi-dimensional quantum well cspbx3 perovskite nanocrystalline light-emitting diode | |
| KR20040016531A (en) | White organic light-emitting materials prepared by light-doping and electroluminescent devices using the same | |
| CN110190200B (en) | Efficient pure white light organic electroluminescent device with high color rendering index and preparation method thereof | |
| CN111916572B (en) | Perovskite light-emitting diode with mixed cations and mixed anions and preparation method thereof | |
| CN112993177B (en) | Blue-light perovskite light-emitting diode and preparation method thereof | |
| CN111916571A (en) | Red perovskite light emitting diode based on mixed halogen and preparation method thereof | |
| CN113437227A (en) | Light-emitting film, preparation method and electroluminescent device | |
| KR100897260B1 (en) | White emitting nanoparticles?dispersion and organic photoelectric device thereby | |
| CN111785846A (en) | Green-light perovskite light-emitting diode based on surface post-treatment process and preparation | |
| CN113421966A (en) | Polyethylene oxide-doped quasi-two-dimensional perovskite thin film, preparation method thereof and light-emitting device | |
| CN109659442B (en) | Organic electroluminescent device and display device | |
| CN111384302A (en) | Full-solution preparation method of fibrous inorganic perovskite quantum dot light-emitting diode | |
| CN112968137B (en) | Perovskite light-emitting diode and preparation method thereof | |
| CN114540028A (en) | Preparation method based on modified bismuth-based perovskite quantum dot material and electroluminescent device | |
| CN113594383A (en) | Blue-light perovskite light-emitting diode based on modified hole transport layer and preparation method thereof | |
| CN111584729A (en) | Organic electroluminescent device and preparation method thereof | |
| CN113394360B (en) | Blue light film and preparation method thereof, and blue light device and preparation method thereof | |
| CN109111456B (en) | Iridium complex used as phosphorescent material, preparation method and application thereof | |
| CN111900239A (en) | Full-inorganic perovskite red light emitting diode based on cuprous iodide addition | |
| KR20040003199A (en) | Organic electroluminescent device comprising a luminescent layer having a dopant with high bandgap | |
| Bhatnagar | Organic Light-Emitting Diodes—A | |
| CN116490019A (en) | Efficient solution processing type blue-green light organic light-emitting device | |
| CN118368915A (en) | Small-molecule doped perovskite light-emitting diode and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20201016 |
|
| RJ01 | Rejection of invention patent application after publication |