Abstract The Sn-based perovskite light-emitting diodes (PeLED) with the structure of (ITO)/MoO3/4,4′-cyclohexylidenebis[N,N-bis(p-tolyl)aniline](TAPC)/4,4′,4′-Tris(carbazol-9-yl)-triphenylamine (TCTA)/perovskite/1,3,5-Tri(m-pyrid-3-yl-phenyl)benzene (TmPyPB)/lithium fluoride(LiF)/Al were fabricated by thermal evaporation and in-situ annealing. The perovskite emitting layers were annealed at the various temperature of 50, 75 and 85 °C during the dual sources thermal evaporation of CsBr and SnBr2 instead of routine post-synthetic annealing for the formation of crystalline CsSnBr3 film. The effects of annealing temperature on the morphology, structure and photophysical properties of the CsSnBr3 perovskite films as well as the electroluminescence(EL) performance of the PeLED were investigated. Little temperature dependence of perovskite emitting layers' morphology was found while obviously intensified absorbance, crystallinity and steady-state photoluminesce(PL) as well as apparently increased PL decay lifetime and slight red-shifted PL spectra of the CsSnBr3 perovskite films upon increasing in-situ annealing temperature were demonstrated. The similar temperature dependent behavior of steady-state PL intensity, transient PL decay life time and photoluminescence quantum yield(PLQY) of all the CsSnBr3 films verified that the hybrid effect of suppressed deep acceptor states and enhanced emitting from shallow trap states would be responsible for the PL behavior of in-situ annealed CsSnBr3 films. In-situ annealing was also capable of extending carriers lifetime and reducing trap density, and leading to the occurrence of the suppressed “self-doping” of Sn4+ and reduction of acceptor states. Meanwhile, the improved crystal quality of the CsSnBr3 nanocrystals should be closely related to the enhanced charge carriers dynamics and improved PL performance. The PeLED with 85 °C in-situ annealed CsSnBr3 emitting layer demonstrated optimal EL performance with the current efficiency(CE) of 0.34 cd/A and external quantum efficiency(EQE) of 0.16%, which was consistent with the annealing temperature dependence of PL behavior of the CsSnBr3 perovskite emitting layer and could be attributed to its superior PL performance, low trap density and high crystallinity.

中文翻译：

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原位退火对热蒸发法制备的锡基钙钛矿发光二极管电致发光性能的影响

摘要 具有(ITO)/MoO3/4,4'-亚环己基双[N,N-双(对甲苯基)苯胺](TAPC)/4,4'结构的Sn基钙钛矿发光二极管(PeLED) ,4'-三(咔唑-9-基)-三苯胺(TCTA)/钙钛矿/1,3,5-三(间-吡啶-3-基-苯基)苯(TmPyPB)/氟化锂(LiF)/Al通过热蒸发和原位退火制造。在 CsBr 和 SnBr2 的双源热蒸发过程中，钙钛矿发光层在 50、75 和 85°C 的不同温度下退火，而不是用于形成结晶 CsSnBr3 薄膜的常规合成后退火。研究了退火温度对CsSnBr3钙钛矿薄膜的形貌、结构和光物理性质以及PeLED电致发光（EL）性能的影响。发现钙钛矿发光层形态对温度的依赖性很小，而随着原位增加，CsSnBr3钙钛矿薄膜的吸光度、结晶度和稳态光致发光（PL）明显增强，PL衰变寿命明显增加，PL光谱轻微红移证明了退火温度。所有 CsSnBr3 薄膜的稳态 PL 强度、瞬态 PL 衰变寿命和光致发光量子产率 (PLQY) 的类似温度依赖性行为证实，抑制深受体态和增强浅陷阱态发射的混合效应将负责原位退火 CsSnBr3 薄膜的 PL 行为。原位退火还能够延长载流子寿命并降低陷阱密度，并导致抑制 Sn4+ 的“自掺杂”和受主态的减少。同时，CsSnBr3 纳米晶体晶体质量的提高应该与增强的电荷载流子动力学和改进的 PL 性能密切相关。具有 85 °C 原位退火 CsSnBr3 发光层的 PeLED 表现出最佳 EL 性能，电流效率 (CE) 为 0.34 cd/A，外量子效率 (EQE) 为 0.16%，这与 PL 的退火温度依赖性一致CsSnBr3 钙钛矿发光层的行为可以归因于其优异的 PL 性能、低陷阱密度和高结晶度。CsSnBr3 纳米晶体的晶体质量提高应该与增强的电荷载流子动力学和改进的 PL 性能密切相关。具有 85 °C 原位退火 CsSnBr3 发光层的 PeLED 表现出最佳 EL 性能，电流效率 (CE) 为 0.34 cd/A，外量子效率 (EQE) 为 0.16%，这与 PL 的退火温度依赖性一致CsSnBr3 钙钛矿发光层的行为可以归因于其优异的 PL 性能、低陷阱密度和高结晶度。CsSnBr3 纳米晶体的晶体质量提高应该与增强的电荷载流子动力学和改进的 PL 性能密切相关。具有 85 °C 原位退火 CsSnBr3 发光层的 PeLED 表现出最佳 EL 性能，电流效率 (CE) 为 0.34 cd/A，外量子效率 (EQE) 为 0.16%，这与 PL 的退火温度依赖性一致CsSnBr3 钙钛矿发光层的行为可以归因于其优异的 PL 性能、低陷阱密度和高结晶度。