Yan Lei, Xue Qifan, Liu Meiyue, Zhu Zonglong, Tian Jingjing, Li Zhenchao, Chen Zhen, Chen Ziming, Yan He, Yip Hin-Lap, Cao Yong
Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China.
Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, 999077, Hong Kong.
Adv Mater. 2018 Jul 3:e1802509. doi: 10.1002/adma.201802509.
In this work, a SnO /ZnO bilayered electron transporting layer (ETL) aimed to achieve low energy loss and large open-circuit voltage (V ) for high-efficiency all-inorganic CsPbI Br perovskite solar cells (PVSCs) is introduced. The high-quality CsPbI Br film with regular crystal grains and full coverage can be realized on the SnO /ZnO surface. The higher-lying conduction band minimum of ZnO facilitates desirable cascade energy level alignment between the perovskite and SnO /ZnO bilayered ETL with superior electron extraction capability, resulting in a suppressed interfacial trap-assisted recombination with lower charge recombination rate and greater charge extraction efficiency. The as-optimized all-inorganic PVSC delivers a high V of 1.23 V and power conversion efficiency (PCE) of 14.6%, which is one of the best efficiencies reported for the Cs-based all-inorganic PVSCs to date. More importantly, decent thermal stability with only 20% PCE loss is demonstrated for the SnO /ZnO-based CsPbI Br PVSCs after being heated at 85 °C for 300 h. These findings provide important interface design insights that will be crucial to further improve the efficiency of all-inorganic PVSCs in the future.
在这项工作中，引入了一种用于高效全无机CsPbI₃Br钙钛矿太阳能电池（PVSCs）的SnO₂/ZnO双层电子传输层（ETL），旨在实现低能量损失和大的开路电压（V）。在SnO₂/ZnO表面可以实现具有规则晶粒和完全覆盖的高质量CsPbI₃Br薄膜。ZnO较高的导带最小值有助于在钙钛矿和具有优异电子提取能力的SnO₂/ZnO双层ETL之间实现理想的级联能级排列，从而抑制界面陷阱辅助复合，降低电荷复合率并提高电荷提取效率。优化后的全无机PVSC提供了1.23 V的高V和14.6%的功率转换效率（PCE），这是迄今为止基于Cs的全无机PVSCs报道的最佳效率之一。更重要的是，基于SnO₂/ZnO的CsPbI₃Br PVSCs在85°C下加热300小时后表现出良好的热稳定性，PCE损失仅为20%。这些发现提供了重要的界面设计见解，这对于未来进一步提高全无机PVSCs的效率至关重要。
