Two‐Step Deposition Approach for Lead Free (NH4)3Sb2I9 Perovskite Solar Cells with Enhanced Open Circuit Voltage and Performance

Abstract In recent years, development of lead (Pb) free perovskite solar cells (PSCs) has attracted the scientific community because of their stability in air and less toxic nature. Antimony (Sb) based perovskite like‐materials such as (CH 3 NH 3 ) 3 Sb 2 I 9 and (NH 4 ) 3 Sb 2 I 9 have been employed as light absorbers and showed promising features for photovoltaic applications. Herein, we have utilized (NH 4 ) 3 Sb 2 I 9 as light absorber for the construction of Pb free PSCs. Moreover, we have employed a modified two step procedure for the preparation of (NH 4 ) 3 Sb 2 I 9 . The developed Pb free PSCs device ( FTO/CL‐TiO 2 /m‐TiO 2 /(NH 4 ) 3 Sb 2 I 9 /HTM/Au ) exhibited enhanced power conversion efficiency (PCE) of 0.42 % with open circuit voltage (Voc) of 945 mV.