钙钛矿太阳电池的界面紫外稳定化研究进展及应对策略

Research Progress and Countermeasures on the Interfacial Ultraviolet Stabilization of Perovskite Solar Cells

针对高效n-i-p结构钙钛矿太阳电池中突出的TiO_(2)/钙钛矿界面紫外不稳定问题,分析其产生的主要原因,讨论了当前研究中从在电池中添加下转换荧光材料和全覆盖TiO_(2)表面两方面来实现电池稳定性过程中存在的问题。比较发现,金属盐是一种合适的钝化材料,然而溶液法制备的金属盐薄膜无法对TiO_(2)实现全覆盖,进一步分析给出金属盐不易全覆盖的主要原因,即存在于微液膜内金属盐前驱体的结晶行为不可控,以及钙钛矿溶液对已制备的金属盐薄膜具有溶解性。就实现金属盐对TiO_(2)表面的全覆盖提出2个步骤的应对策略,第一步利用低压腔室装置实现超快结晶,即制备“全”覆盖;第二步通过巯基苯吸附构建非相溶表面,即保护“全”覆盖。最后,针对TiO_(2)/CsX/钙钛矿界面的紫外稳定性提出具体研究方法和策略。建立了一套提高电池紫外稳定性的金属盐微结构调控与电池界面全面钝化的应对策略,这些将为电池常态化应用中所面临的稳定性问题提供理论和技术支撑。

This paper focuses on the prominent UV instability of TiO_(2)/perovskite interface in efficient n-i-p structured perovskite solar cells,and the main reasons are analyzed.In addition,the main problems are analyzed and discussed in the process of adding down-conversion fluorescent materials and fully covering the TiO_(2) surface to achieve the stability of the perovskite solar cells.By comparison,metal salt is a suitable passivation material.However,metal salt films are unable to fully cover TiO_(2),which is prepared by solution method.Further analysis gives the main reasons why metal salt is not easy to cover completely.There are two aspects of uncontrollable crystallization behavior of metal salt precursors in micro-liquid film and solubility of perovskite solution to the prepared metal salt film.In this paper,a two-step strategy is proposed to achieve full coverage of metal salt on TiO_(2) surface.The first step has achieved ultrafine crystallization by using a low-pressure chamber device,that is,to preparing the"full"coverage.The second step has constructed a non-soluble surface by mercaptobenzene adsorption,that is,to protect the"full"coverage.Finally,specific research methods and strategies are proposed for the UV stability of TiO_(2)/CsX/perovskite interface.In this paper,a set of coping strategies are established to improve the UV stability of the perovskite solar cells by adjusting the metal salt microstructure and the interface passivation.These will provide theoretical and technical support for the stability issues faced in the normal application of perovskite solar cells.