新型有机-无机复合层状钙钛矿晶体及其光电器件的稳定性研究

Organic-inorganic hybrid perovskite materials have generated a great deal of interest because of their potential in the optoelectronic applications. However, stability is the most prominent problem in the hybrid perovskite materials and devices. Although some research group mainly improved the device stability by the interface engineering and device structure design and so on, none of them are devoted to the systematic research of the stability of hybrid perovskite materials in term of their single crystals. This project is aimed to introduce the aromatic ammonium (C6H5CH2CH2NH3+ or C6H5CH(CH3)NH3+) into CH3NH3PbX3 (X= Cl, Br, I) materials to tackle with these questions. The bulk growth of layered hybrid perovskite single crystals is carried out with seed crystal by temperature-lowering method in ambient atmosphere. The intrinsic properties, and the stability mechanism of these hybrid perovskite single crystals when exposed to the air and light conditions are demonstrated in detail. Moreover, the stability of the hybrid perovskite single-crystalline optoelectronic devices is also studied. The purpose of this project is not only to break through the research limitations of these materials based on the thin film or powders, but also to provide the important guidance for understanding the fundamental properties and stability of the hybrid perovskite single crystals and their related single-crystalline devices and expanding the applications of new hybrid perovskite materials in the optoelectronic fields.

有机-无机复合钙钛矿材料在光电领域具有很好的应用前景，引起国内外研究者的关注。然而，在有机-无机复合钙钛矿材料以及器件方面存在着最突出的问题是稳定性。虽然国内外研究组主要从界面工程以及器件结构设计等角度来提高器件的稳定性，但是很少从晶体角度对有机-无机复合钙钛矿材料的稳定性进行系统地研究。本项目拟通过引入含苯环有机胺类阳离子来提高CH3NH3PbX3(X=Cl, Br, I)稳定性这一研究思路，采用籽晶-溶液降温的方法进行此类层状钙钛矿晶体的生长，并对此类层状晶体材料的本征性能以及在空气、光照条件下稳定性的机理进行系统地研究，开展相关单晶光电器件(太阳能电池、发光二极管和光探测器等)稳定性的研究。本项目的开展将突破此类材料仅限于薄膜或粉末的限制，对理解钙钛矿晶体材料的基本性能及相关单晶光电器件的稳定性，以及拓展新型钙钛矿材料在光电领域应用具有重要的指导意义。

有机-无机复合层状含铅钙钛矿晶体材料在光电领域具有很好的应用前景。本项目在执行过程中，总体按照项目计划的内容进行开展的，基本达到预期的研究目标。本项目以有机-无机复合层状钙钛矿晶体材料及其发光性能与稳定性问题为中心，从晶体学的角度设计并合成生长了一系列大尺寸有机-无机复合钙钛矿晶体，系统地研究了它们的结构相变、光学性能(例如手性光学特性等)与稳定性问题。更重要地是，主要开展了有关手性苯乙胺(C6H5CH(CH3)NH2)类系列含铅钙钛矿晶体的生长、非线性光学以及手性光学特性的研究。同时，通过引入苯乙胺(C6H5CH2CH2NH2)和类卤素离子(SCN-)到甲胺铅碘 (CH3NH3PbI3) 中构筑不同钙钛矿结构的晶体，并且对它们的相变、发光特性与稳定性进行系统地研究。此工作的开展不仅对手性以及层状钙钛矿晶体的制备与基本物理特性有着深入认识，还对此类晶体材料在光电应用具有重要的指导意义。此外，在本项目资助下，在国际权威的学术期刊上发表SCI论文6篇，相关研究工作得到国内外同行专家的积极评价和认可。