Red perovskite light emitting diode based on mixed halogen and preparation method thereof

A technology of light-emitting diodes and perovskites, which is applied in semiconductor/solid-state device manufacturing, electrical components, circuits, etc., can solve the problems of poor spectral stability and low efficiency of red light devices, so as to reduce movement, improve charge transport performance, and improve Effects of Brightness and Efficiency

Active Publication Date: 2020-11-10
SOUTH CHINA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Red devices based on mixed halogens are generally inefficient and have poor spectral stability
Although the efficiency of red light devices based on dimension control is high, the brightness still needs to be further improved.

Method used

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  • Red perovskite light emitting diode based on mixed halogen and preparation method thereof
  • Red perovskite light emitting diode based on mixed halogen and preparation method thereof
  • Red perovskite light emitting diode based on mixed halogen and preparation method thereof

Examples

Experimental program
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Effect test

Embodiment 1

[0056] This embodiment provides a red-light perovskite light-emitting diode mixed with halogen. The formation of the perovskite layer uses ethyl acetate as an anti-solvent to accelerate the crystallization of the perovskite. It sequentially includes a glass substrate, an anode, a hole injection layer, a hole transport layer 1, a hole transport layer 2, a red perovskite light-emitting layer, an electron transport layer, an electron injection layer and a cathode. The preparation method is as follows:

[0057] (1) According to CsI is 0.3mol / L, PbI 2 The perovskite precursor solution was prepared at a concentration of 0.3mol / L and PEABr of 0.18mol / L, and the solvent used was DMSO.

[0058] (2) After the cleaned ITO glass was placed in a UV ozone cleaning machine for 15 minutes, the commercial PEDOT:PSS aqueous solution was directly spin-coated on the treated ITO glass at a speed of 4000rpm. The spin-coating time was 30 seconds, and Annealed at 150°C for 30 minutes to obtain a PED...

Embodiment 2

[0071] The device structure and preparation method of the perovskite light-emitting diode in this embodiment are basically the same as in Example 1, and ethyl acetate is used as the anti-solvent. The difference is that the ratio CsI of the perovskite precursor solution in this embodiment is 0.3mol / L, PbI 2 The concentration is 0.36mol / L and PEABr is 0.18mol / L. That is, compared to Pb / Cs=1 in Example 1, Pb / Cs=1.2 in this example.

[0072] according to Figure 10 In (b) and (c), it can be seen that in the formation process of red light perovskite, a slight excess of Pb over Cs is more conducive to the crystallization of the perovskite film, and the perovskite film with Pb / Cs=1.2 is more favorable than Pb / The perovskite film with Cs=1 can form more columnar crystal structures, and the performance comparison in Table 2 and Figure 5 and Figure 6 It can be seen that this columnar crystal has a great impact on the performance of the device. After a slight excess of Pb over Cs,...

Embodiment 3

[0076] The device structure and preparation method of the perovskite light-emitting diode in this embodiment are basically the same as in Example 1, and the concentration of each anion and cation in the perovskite precursor solution is also the same, the difference is that in the precursor solution of this embodiment Br - From lead bromide (PbBr 2 ). The ratio of each component is shown in Table 3

[0077] Table 3. Comparison of the distribution ratio of each component of the red light perovskite precursor solution (unit: mol / L)

[0078]

[0079] According to Table 4 and Figure 7 as well as Figure 8 The results in show that under the same ionic composition of the red light perovskite, the Br - From PbBr 2 The performance of the device is better, the maximum external quantum efficiency can reach 16%, and the maximum brightness can reach 3631 candela / square meter.

[0080] Table 4. Comparison of device performance parameters of red perovskite light-emitting diodes

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Abstract

The invention discloses a red perovskite light-emitting diode based on mixed halogen and a preparation method thereof. The light-emitting diode sequentially comprises a transparent substrate, an anode, a hole injection layer, a hole transport layer 1, a hole transport layer 2, a perovskite light-emitting layer, an electron transport layer, an electron injection layer and a cathode, wherein the perovskite light-emitting layer is prepared by spin-coating a perovskite precursor solution; dropwise adding an anti-solvent in the spin coating process, wherein the perovskite precursor solution is prepared by dissolving cesium iodide CsI, cesium bromide CsBr, lead bromide PbBr2, lead iodide PbI2, organic ammonium bromide salt LBr and organic ammonium iodide salt LI in a polar solvent. By combininglarge-size organic cations with mixed halogens, the generation of a non-luminous active perovskite phase is inhibited, the movement of halogen ions is reduced, and the spectral stability is realized while the brightness and efficiency of the red perovskite LED are improved.

Description

technical field [0001] The invention belongs to the technical field of optoelectronic devices, and in particular relates to a red-light perovskite light-emitting diode based on mixed halogen and a preparation method thereof. Background technique [0002] A light emitting diode (light emitting diode, LED), as an electro-optical conversion semiconductor device, is widely used in fields such as display and lighting. As a new type of photoelectric conversion material, metal halide perovskite has been widely used in LED in recent years due to its characteristics of good conductivity, high fluorescence quantum efficiency, narrow emission spectrum, easy adjustment of band gap, low raw material cost and solution processing. It has been successfully applied and has aroused great concern of people. [0003] External quantum efficiency and brightness are important parameters to measure the performance of LED devices. Since 2014, although the performance of perovskite LEDs has continu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L51/50H01L51/52H01L51/54H01L51/56
CPCH10K85/00H10K50/14H10K50/80H10K50/11H10K2102/00H10K71/00
Inventor 陈江山马东阁张灯亮杨德志乔现锋
Owner SOUTH CHINA UNIV OF TECH
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