[15p-A401-1~17] 12.5 Organic and hybrid solar cells

▲ [15p-A401-1] Sequential Passivation for Lead-Free Tin Perovskite Solar Cells with High Efficiency

〇(D)Zheng Zhang¹, Qing Shen¹, Shuzi Hayase¹ (1.University of Electro-Communication)

Keywords:Tin halide perovskite

Lead-free tin perovskite solar cells (PKSCs) have been demonstrated to get tremendous interest to replace the more toxic lead-based PKSCs. Nevertheless, the efficiency is significantly lower than that of lead-based PKSCs due to the rough surface morphology and more defects and traps, which caused by the fast crystallization and easy oxidization of tin perovskite materials. Herein, a facile and universal post treatment strategy is proposed by the sequential passivating perovskite surface with acetylacetone (ACAC) and ethylenediamine (EDA). The results show that the ACAC treatment can reduce the trap density and enlarge the grain size (short-circuit current (J_sc) enhancement), while the EDA treatment can bond the undercoordinated tin, as well as regulate the energy level (open-circuit voltage (V_oc) enhancement). 13% power conversion efficiency was realized by the synergies of ACAC and EDA. The device also demonstrated better long-term stability. In addition, the other families of materials with diketones and amines functional groups have also shown similar effect, and the strategy can also expand to other type PKSCs system. This study gives a universal strategy to enhance the crystallinity, passivate defects, fabricate efficient and stable PKSCs.