铯铅卤化物钙钛矿型平面异质结LED的应用与发展

doi:10.15541/jim20180176

摘要/Abstract

摘要：

由于优异的光电性能与环境稳定性, 全无机铯铅卤化物CsPbX₃(X=Cl, Br, I)钙钛矿材料自2015年起逐渐成为光电领域的研究热点, 在诸多电子、光电子器件的应用研究中取得了突破性进展, 受到了科学界的广泛关注。本综述结合铯铅卤化物钙钛矿型平面异质结LED的最新研究进展, 对器件的结构及其工作原理进行扼要的介绍, 并着重从提高LED器件发光性能和工作稳定性方面进行优化策略的归类与总结, 最后就稳定高效的无机钙钛矿型平面异质结LED的发展趋势进行了展望。

关键词: 铯铅卤化物钙钛矿, 平面异质结, LED, 稳定性, 掺杂, 综述

Abstract:

All-inorganic cesium lead halide CsPbX₃ (X = Cl, Br, I) perovskite materials emerged as a rising star in the area of optoelectronics since 2015, due to its excellent photoelectric properties and environmental stability. Substantial progresses were made in the application of many electronic and optoelectronic devices, which attracted wide attention from the scientific community. This paper mainly reviews the latest research progress of cesium lead halide perovskite based planar heterojunction LED, where the structure and working principle of LED devices are briefly introduced. In addition, the classification and summarization of some optimization strategies for improving luminescence performance and working stability of LED devices are emphatically suggested, and the development trend of stable and efficient inorganic perovskite based planar heterojunction LED is finally prospected.

Key words: cesium lead halide perovskite, planar heterojunction, LED, stability, doping, review

中图分类号:

O472

章楼文, 沈少立, 李露颖, 张智, 刘逆霜, 高义华. 铯铅卤化物钙钛矿型平面异质结LED的应用与发展[J]. 无机材料学报, 2019, 34(1): 37-48.

ZHANG Lou-Wen, SHEN Shao-Li, LI Lu-Ying, ZHANG Zhi, LIU Ni-Shuang, GAO Yi-Hua. Application and Development of Cesium Lead Halide Perovskite Based Planar Heterojunction LEDs[J]. Journal of Inorganic Materials, 2019, 34(1): 37-48.

图/表 9

图1 LED器件发光性能和稳定性的优化策略

Fig. 1 Optimization strategies for luminescence performance and stability of LED devices

图2 钙钛矿型平面异质结LED的器件结构示意图(a)~(b)和工作机理示意图(c)

Fig. 2 Schematic diagram of the device structures (a, b) and working mechanism (c) for perovskite based planar heterojunction LEDs

图3 (a)器件的结构示意图; (b)器件横截面的TEM照片, 比例尺: 50 nm; (c)器件的能带示意图; (d)器件在外加电压为5 V时的EL光谱(实线)和量子点分散在己烷中的PL(光致发光)光谱(虚线)[58]

Fig. 3 (a) Schematic diagram of device structure; (b) Cross-sectional TEM image. Scale bar, 50 nm; (c) Flat-band energy level diagram; (d) The EL spectra (straight line) of devices for CsPb(Cl/Br)3, CsPbBr3 and CsPb(Br/I)3 under applied voltage of 5.5 V, and the photoluminescence (PL) spectra (dashed line) of QDs dispersed in hexane[58]

图4 (a)器件的结构示意图和横断面的TEM照片(比例尺: 50 nm); (b)两次净化处理后CsPbBr3的QLEDs的EL光谱(实线)和PL光谱(虚线), 插图: 外加电压为5 V时的工作器件照片; (c)器件的EQE随发光强度的变化曲线[59]

Fig. 4 (a) Schematic illustration of device structure and a cross-sectional TEM image (scale bar: 50 nm); (b) Normalized EL spectra (solid lines) and PL spectra (dashed lines) of CsPbBr3 QLEDs with two purifying cycles. Inset in (b): The photograph of a working device at an applied voltage of 5 V; (c) EQE of these devices for QDs with different purifying cycles as a function of luminance[59]

图5 (a)CsPbBr3钙钛矿型LED的结构示意图; (b)CE和EQE随电压变化的特征曲线[68]; (c)无处理和(d)氯苯处理后的CsPbBr3薄膜表面形貌及其LED表面发光照片[69]

Fig. 5 (a) Structural representation of CsPbBr3 based LEDs; (b) Current efficiency-voltage (CE-V), and EQE-voltage (EQE-V) characteristic curves[68]; The surface morphology of CsPbBr3 film and surface luminous photo of LED (c) without treatment and (d) with chlorobenzene treatment[69]

图6 (a)不同ETL和HTL材料构筑器件的EQE和CE与电压的变化关系[77]; (b)不同PEG和CsPbBr3(CsBr和PbBr2摩尔比为1.4:1)质量比构筑的LED器件的EQE-V曲线[78]; (c)器件的结构示意图和横断面的TEM照片; (d)有无Ag纳米棒修饰的LED器件的EQE[79]

Fig. 6 (a) EQE and CE as a function of voltage among devices fabricated with different ETL and HTL materials[77]; (b) EQE-V curves for the LEDs with different PEG:CsPbBr3 (CsBr:PbBr2 molar ratio of 1.4:1) weight ratios[78]; (c) TEM image of cross section of device and corresponding schematic diagram of device structure; (d) EQE for the devices with and without Ag rod[79]

图7 (a)LED器件各组分的能带示意图; (b)有无PFI界面修饰层器件的EQE和CE与电流密度的变化关系曲线[85]; (c)器件的结构示意图; (d)不同组分构成的器件的CE和EQE随电流密度的变化曲线[51]

Fig. 7 (a) Overall energy band diagram of the LED structure; (b) EQE and CE vs current density of devices with or without PFI interface modifier[85]; (c) Schematic diagram of device structure; (d) CE and EQE of devices with and without PVP buffer layer, with and without CH3NH3Br (MABr) additive[51]

图8 (a)器件的结构示意图; (b)器件的EQE随亮度的变化[90]; (c)能带示意图; (d)EQE随电压的变化[91]

Fig. 8 (a) Schematic illustration of device structure; (b) EQE of the devices as a function of luminance[90]; (c) Band alignment of each functional layer; (d) EQE of the devices as a function of driving voltage[91]

图9 (a) LED器件的能带示意图; (b)发光效率与电压、EQE与电压的变化关系曲线[99]; (c)溶液法制备的LED的结构示意图; (d) EQE、CE和发光效率随电压的变化曲线[102]

Fig. 9 (a) Simplified energy band alignment of the LED; (b) Luminous efficiency and EQE versus voltage of the LED[99]; (c) Schematic illustration of solution-processed perovskite LED; (d) EQE, CE, and power efficiency versus voltage of the LED[102]

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