Wu Guohua, Li Hua, Chen Shuai, Liu Shengzhong Frank, Zhang Yaohong, Wang Dapeng
Qingdao Innovation and Development Base of Harbin Engineering University, Harbin Engineering University, Harbin 150001, China.
Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Laboratory for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an 710119, China.
Nanomaterials (Basel). 2022 Nov 3;12(21):3881. doi: 10.3390/nano12213881.
Amidinium salts have been utilized in perovskite precursor solutions as additives to improve the quality of perovskite films. The design of hydrophilic or hydrophobic groups in amidinium salts is of great importance to photovoltaic device performance and stability in particular. Here we report a contrast study of a guanidinium iodide (GUI) additive with a hydrophilic NH group, and a N,1-diiodoformamidine (DIFA) additive with a hydrophobic C-I group, to investigate the group effect. The addition of GUI or DIFA was beneficial to achieve high quality perovskite film and superior photovoltaic device performance. Compared with GUI, the addition of the DIFA in a perovskite precursor solution enhanced the crystal quality, reduced the defect density, and protected the water penetration into perovskite film. The perovskite solar cell (PSC) devices showed the best power conversion efficiency (PCE) of 21.19% for those modified with DIFA, as compared to 18.85% for the control, and 20.85% for those modified with GUI. In benefit to the hydrophobic C-I group, the DIFA-modified perovskite films and PSC exhibited the best light stability, thermal stability, and humidity stability in comparison to the control films and GUI-modified films. Overall, the introduction of a hydrophobic group in the amidinium salts additive was demonstrated to be an efficient approach to achieve high quality and stable perovskite film and PSC devices.
脒盐已被用作钙钛矿前驱体溶液中的添加剂，以提高钙钛矿薄膜的质量。脒盐中亲水或疏水基团的设计对光伏器件的性能，尤其是稳定性至关重要。在此，我们报告了一项对比研究，研究具有亲水NH基团的碘化胍（GUI）添加剂和具有疏水C-I基团的N,1-二碘甲脒（DIFA）添加剂，以研究基团效应。添加GUI或DIFA有利于获得高质量的钙钛矿薄膜和优异的光伏器件性能。与GUI相比，在钙钛矿前驱体溶液中添加DIFA提高了晶体质量，降低了缺陷密度，并防止了水渗透到钙钛矿薄膜中。钙钛矿太阳能电池（PSC）器件中，用DIFA改性的器件表现出最佳的功率转换效率（PCE），为21.19%，而对照组为18.85%，用GUI改性的为20.85%。得益于疏水的C-I基团，与对照薄膜和GUI改性薄膜相比，DIFA改性的钙钛矿薄膜和PSC表现出最佳的光稳定性、热稳定性和湿度稳定性。总体而言，在脒盐添加剂中引入疏水基团被证明是获得高质量和稳定的钙钛矿薄膜及PSC器件的有效方法。
