Luo Tianyuan, Chen Rui, Zhang Gaojie, Li Luji, Wu Hao, Zhang Wenfeng, Chen Wei, Chang Haixin
State Key Laboratory of Material Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Shenzhen R&D Center of Huazhong University of Science and Technology, Shenzhen 518000, PRC.
ACS Appl Mater Interfaces. 2023 Aug 16;15(32):38496-38506. doi: 10.1021/acsami.3c07902. Epub 2023 Aug 3.
The fabrication of α-FAPbI perovskite films usually requires high temperature annealing above 150 °C, and the residual tensile strain in the films seriously affects the stability of α-FAPbI by converting to δ-phase FAPbI. Here, we use MASCN surface treatment of FAPbI films to induce a rotation of the coplanar octahedron [PbI] to the metric octahedron for the strong interaction of SCN with Pb, converting δ-FAPbI into α-FAPbI highly crystalline films at room temperature. The optimized FAPbI films have high stability due to releasing residual tensile strains after MASCN treatment. The efficiency of the MASCN-treated unannealed FAPbI PSC is 19.03%, while the optimized FAPbI annealed at 100 °C shows a maximum PCE of 21.95% on a small area. The solar cell stability for humidity, light, and thermal stability are significantly improved. The MASCN treated FAPbI achieves a PCE of 15.32% on a PSC module with an effective area of 9.6 cm and maintains an initial efficiency of 94.1% after 100 days of ageing at 85 °C and 85% humidity.
α-FAPbI钙钛矿薄膜的制备通常需要在150°C以上进行高温退火，并且薄膜中的残余拉伸应变会通过转变为δ相FAPbI严重影响α-FAPbI的稳定性。在此，我们对FAPbI薄膜进行MASCN表面处理，以诱导共面八面体[PbI]向计量八面体旋转，从而使SCN与Pb发生强相互作用，在室温下将δ-FAPbI转化为α-FAPbI高结晶度薄膜。经过MASCN处理后，优化后的FAPbI薄膜由于释放了残余拉伸应变而具有高稳定性。未经退火的MASCN处理的FAPbI PSC的效率为19.03%，而在100°C下退火的优化后的FAPbI在小面积上的最大光电转换效率（PCE）为21.95%。其在湿度、光照和热稳定性方面的太阳能电池稳定性得到显著提高。经MASCN处理的FAPbI在有效面积为9.6平方厘米的PSC模块上实现了15.32%的PCE，并且在85°C和85%湿度下老化100天后保持了94.1%的初始效率。
