摘要
二维铅卤钙钛矿太阳能电池以其高稳定性等优良性质展现出重要的应用价值,越来越多的二维铅卤钙钛矿材料被用作太阳能电池的光吸收层,但是关于二维铅卤钙钛矿材料构效关系的理论研究十分匮乏.本文以苯甲胺铅碘、邻氟苯甲胺铅碘和对氟苯甲胺铅碘二维钙钛矿为出发点,通过第一性原理计算比较了它们的晶体结构、形成能、激子结合能、载流子迁移率以及对应器件的光电性能,以考察不同间隔基阳离子对钙钛矿结构、性质以及光电器件性能的影响.结果表明,二维钙钛矿的形成能绝对值越大,光电器件的稳定性越高;钙钛矿的激子结合能越小,光电器件的短路电流密度越大,归纳总结出预测器件短路电流密度的关系式.在间隔基末端使用吸电子基团修饰有望同时提高光电器件的寿命和短路电流密度.本研究对于二维钙钛矿材料有机间隔阳离子的设计和筛选具有指导意义.
Two-dimensional lead halide perovskite solar cell has shown great potential applications because of its relatively high stability in comparison with normal three-dimensional perovskite.More and more twodimensional lead halide perovskites are used as absorbers in solar cells,but theoretical study on the structureperformance relationship of two-dimensional lead halide perovskites is still lacking.Therefore,starting form 3 kinds of fluorobenzylamine perovskites,first-principle calculations are carried out.By comparing their crystal structures,non-covalent interactions,formation energy,band structures,exciton binding energy,carrier mobilities of theses perovskites,and short-circuit current densities of their corresponding solar cells,the influences caused by organic spacers on the structural and electronic properties are studied.This research shows that the more negative the formation energy,the higher the stability of the optoelectronic device is,and the smaller the exciton binding energy,the larger the short-circuit current of the optoelectronic device is.A relationship for quantitative prediction of short-circuit current is proposed,and substitution with electronwithdrawing groups at the end of the spacer is expected to improve both the stability and short-circuit current density of optoelectronic device.The research results of this work can contribute to the design of new perovskite solar cells with high conversion efficiency.
作者
隋国民
严桂俊
杨光
张宝
冯亚青
Sui Guo-Min;Yan Gui-Jun;Yang Guang;Zhang Bao;Feng Ya-Qing(School of Chemical Engineering and Technology,Tianjin University,Tianjin 300350,China;Tianjin Co-Innovation Center of Chemical Science and Engineering,Tianjin University,Tianjin 300720,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第20期352-362,共11页
Acta Physica Sinica
基金
国家重点研发计划(批准号:2020YFB0408002)资助的课题。
