Cui Yubo, Wang Mengyang, Dong Peizhe, Zhang Shuangshuang, Fu Junjie, Fan Libo, Zhao Chaoliang, Wu Sixin, Zheng Zhi
Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, College of Chemical and Materials Engineering, Xuchang University, Xuchang, Henan Province, 461000, P. R. China.
School of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo, Henan Province, 454000, P. R. China.
Adv Sci (Weinh). 2022 Jul;9(20):e2201241. doi: 10.1002/advs.202201241. Epub 2022 Apr 28.
A main concern of the promising DMF-based Cu ZnSn(S ,Se ) (CZTSSe) solar cells lies in the absence of a large-grain spanning structure, which is a key factor for high open-circuit voltage (V ) and power conversion efficiency (PCE). A new strategy to achieve CZTSSe large-grain spanning monolayer is proposed, by taking advantage of the synergistic optimization with a Cu plus Sn redox system and pre-annealing temperatures. A series of structural, morphological, electrical, and photoelectric characterizations are employed to study the effects of the pre-annealing temperatures on absorber qualities, and an optimized temperature of 430 ℃ is determined. The growth mechanism of the large-grain spanning monolayer and the effect of redox reaction rate are carefully investigated. Three types of absorber growth mechanisms and a concept of critical temperature are proposed. The devices based on this large-grain spanning monolayer suppress the recombination of carriers at crystal boundaries and interfaces. The champion device exhibits a high V (>500 mV) and PCE of 11.76%, which are both the maximum values among DMF-based solar cells at the current stage.
基于二甲基甲酰胺（DMF）的铜锌锡硫硒（CZTSSe）太阳能电池的一个主要问题在于缺乏大晶粒连续结构，而这是实现高开路电压（V）和功率转换效率（PCE）的关键因素。本文提出了一种实现CZTSSe大晶粒连续单层的新策略，即利用铜加锡氧化还原体系与预退火温度的协同优化。采用一系列结构、形貌、电学和光电表征手段来研究预退火温度对吸收层质量的影响，并确定了430℃的优化温度。详细研究了大晶粒连续单层的生长机制以及氧化还原反应速率的影响。提出了三种类型的吸收层生长机制和临界温度的概念。基于这种大晶粒连续单层的器件抑制了晶体边界和界面处载流子的复合。最佳器件表现出高开路电压（>500 mV）和11.76%的功率转换效率，这两者均为现阶段基于DMF的太阳能电池中的最大值。
