形貌调控实现高效率全无机钙钛矿发光二极管

Inorganic perovskite materials show tremendous application foreground in solid state lighting sources and flat panel displays due to their strong photoluminescence quantum yield，high color purity，simply tunable band gap，high thermal stability and low cost. However, research of inorganic perovskite light-emitting diodes (PeLEDs) has just begun and the performance should be improved urgently. Morphology of perovskite film is of great influence on exciton formation probability, exciton diffusion length, radiative and nonradiative transition probability and carrier transport property. As a result, morphology of perovskite film is one of the key factors affecting luminous efficiency of the inorganic PeLEDs. However，methods and the ways to control perovskite film morphology and its influence on film physical processes have not yet been fully mastered. The goal of this project is to study and master the method to control perovskite film morphology and to construct high-efficient inorganic PeLEDs after finding growth rhythm of perovskite film, deeply studying the related physical process and fully understanding the management mechanisms of morphology on luminescent properties.

全无机钙钛矿发光材料具有发光量子效率高、光谱色纯度高、光谱简单可调、热稳定性好以及成本低廉等一系列优点，显示出其在照明与平板显示领域的巨大应用前景。但是无机钙钛矿发光二极管研究刚刚起步，器件性能亟待提高。钙钛矿薄膜的形貌对激子形成几率、激子扩散长度、辐射与非辐射跃迁几率、载流子传输特性等物理过程具有重要影响。因此，钙钛矿薄膜的形貌是决定器件性能的关键因素之一。但是，目前钙钛矿薄膜的形貌调控方法与途径尚未被完全掌握，同时其对钙钛矿薄膜的物理过程影响也未被深入了解。本项目拟通过探索无机钙钛矿薄膜形貌调控方法，掌握有效调控其形貌的途径，揭示其生长规律，并就其对钙钛矿薄膜相关物理过程的影响进行深入研究，了解其对发光特性调控的机制，在此基础上构建高效率全无机钙钛矿发光二极管。

全无机钙钛矿发光材料具有发光量子效率高、光谱色纯度高、光谱简单可调、热稳定性好以及成本低廉等一系列优点，显示出其在照明与平板显示领域的巨大应用前景。但是基于无机钙钛矿材料的发光二极管研究刚刚起步，器件性能亟待提高。钙钛矿薄膜的形貌对激子形成几率、激子扩散长度、辐射与非辐射跃迁几率、载流子传输特性等物理过程具有重要影响。因此，钙钛矿薄膜的形貌是决定器件性能的关键因素之一。但是，目前钙钛矿薄膜的形貌调控方法与途径尚未被完全掌握，同时其对钙钛矿薄膜的物理过程影响也未被深入了解。项目通过对无机钙钛矿CsPbBr3薄膜的成膜温度、湿度、基底等生长环境以及前驱体溶液的调控，研究了无机钙钛矿薄膜形貌的影响因素及其生长的相关动力学过程；研究了不同形貌无机钙钛矿的电荷传输、能带结构、激子寿命、激子扩散长度和辐射与非辐射跃迁几率等物理特性；研究了不同薄膜形貌下全无机 PeLEDs的光电性能；研究了钙钛矿形貌与全无机PeLEDs发光亮度、电流效率、外量子效率、功率效率等性能之间的关系。在上述研究的基础之上，实现对无机钙钛矿薄膜形貌的目标调控，并通过对薄膜形貌的目标调控构建了高效的全无机PeLEDs，最高亮度达到4500 cd/m2。相关研究成果发表SCI论文7篇，其中影响因子大于3.0的SCI论文5篇。