Li Yun, Zhang Jinghui, Xiang Jin, Hu Hanlin, Zhong Haizhe, Shi Yumeng
International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China.
Hofman Institute of Advanced Materials, Shenzhen Polytechnic, Shenzhen 518055, China.
ACS Appl Mater Interfaces. 2022 May 18;14(19):22324-22331. doi: 10.1021/acsami.1c23115. Epub 2022 May 9.
The efficiency of metal halide perovskite solar cells (PSCs) has dramatically increased over the past decade (formerly 3.8%, now 25.5%). It has been widely demonstrated that the defects passivation of perovskite photo-active layer plays a vital role in increasing the efficiency and improving the stability of PSCs. In this study, we developed a novel 4,4'-bipiperidine (BiPi)-based organic salt with good stability and successfully introduced this ligand into perovskite for the first time. The embedded BiPi-based organic salt in the 3D perovskites facilitated the formation of two-dimensional-three-dimensional (2D-3D) perovskite materials that passivated the perovskite layer, with a constructive consequence in both photovoltaic performance and device stability. Incorporating this ligand improved the crystallinity of the perovskite materials with reduced defect states, prolonged resolved carrier lifetime, and improved stability. An optimized PSC device exhibited substantially improved device stability and an outstanding power conversion efficiency of 20.03%, with the aid of the BiPi-based organic salt [open-circuit voltage (), 1.10 V; current density (), 23.51 mA/cm; and fill factor (FF), 0.77], which are 13.0% higher than the original device. Our study provides a ligand design protocol for developing next-generation, highly efficient, stable PSCs.
在过去十年中，金属卤化物钙钛矿太阳能电池（PSC）的效率大幅提高（以前为3.8%，现在为25.5%）。广泛的研究表明，钙钛矿光活性层的缺陷钝化在提高PSC的效率和稳定性方面起着至关重要的作用。在本研究中，我们开发了一种具有良好稳定性的新型4,4'-联哌啶（BiPi）基有机盐，并首次成功地将这种配体引入到钙钛矿中。嵌入在三维钙钛矿中的BiPi基有机盐促进了二维-三维（2D-3D）钙钛矿材料的形成，该材料钝化了钙钛矿层，对光伏性能和器件稳定性都产生了积极影响。引入这种配体提高了钙钛矿材料的结晶度，减少了缺陷态，延长了载流子寿命，并提高了稳定性。借助BiPi基有机盐，优化后的PSC器件表现出显著提高的器件稳定性和出色的20.03%的功率转换效率[开路电压（），1.10 V；电流密度（），23.51 mA/cm；填充因子（FF），0.77]，比原始器件高出13.0%。我们的研究为开发下一代高效、稳定的PSC提供了一种配体设计方案。
