Gao Weiyin, Ran Chenxin, Li Jingrui, Dong Hua, Jiao Bo, Zhang Lijun, Lan Xuguang, Hou Xun, Wu Zhaoxin
Key Laboratory of Photonics Technology for Information, Key Laboratory for Physical Electronics and Devices of the Ministry of Education, School of Electronic and Information Engineering , Xi'an Jiaotong University , Xi'an 710049 , P.R. China.
Collaborative Innovation Center of Extreme Optics , Shanxi University , Taiyuan 030006 , China.
J Phys Chem Lett. 2018 Dec 20;9(24):6999-7006. doi: 10.1021/acs.jpclett.8b03194. Epub 2018 Dec 3.
The instability issue of Pb-free Sn-based perovskite is one of the biggest challenges for its application in optoelectronic devices. Herein, a structural regulation strategy is demonstrated to regulate the geometric symmetry of formamidiniumtin iodide (FASnI) perovskite. Experimental and theoretical works show that the introduction of cesium cation (Cs) could improve the geometric symmetry, suppress the oxidation of Sn, and enhance the thermodynamical structural stability of FASnI. As a result, the inverted planar Cs-doped FASnI-based perovskite solar cell (PSC) is shown to maintain 90% of its initial power-conversion efficiency (PCE) after 2000 h stored in N, which is the best durability to date for 3D Sn-based PSCs. Most importantly, the air, thermal, and illumination stabilities of the PSCs are all improved after Cs doping. The PCE of the Cs-doped PSC shows a 63% increase compared to that of the control device (from 3.74% to 6.08%) due to the improved quality of the Cs-doped FASnI film.
无铅锡基钙钛矿的不稳定性问题是其在光电器件中应用面临的最大挑战之一。在此，展示了一种结构调控策略来调节碘化甲脒锡（FASnI）钙钛矿的几何对称性。实验和理论研究表明，引入铯阳离子（Cs）可以改善几何对称性，抑制锡的氧化，并增强FASnI的热力学结构稳定性。结果表明，倒置平面Cs掺杂的基于FASnI的钙钛矿太阳能电池（PSC）在氮气中储存2000小时后仍能保持其初始功率转换效率（PCE）的90%，这是迄今为止3D锡基PSC的最佳耐久性。最重要的是，Cs掺杂后PSC的空气稳定性、热稳定性和光照稳定性均得到改善。由于Cs掺杂的FASnI薄膜质量提高，Cs掺杂PSC的PCE相比对照器件提高了63%（从3.74%提高到6.08%）。
