Lead‐free Perovskite Materials (NH₄)₃Sb₂I_xBr_9−x

Abstract

Abstract A family of perovskite light absorbers (NH 4 ) 3 Sb 2 I x Br 9− x (0≤ x ≤9) was prepared. These materials show good solubility in ethanol, a low‐cost, hypotoxic, and environmentally friendly solvent. The light absorption of (NH 4 ) 3 Sb 2 I x Br 9− x films can be tuned by adjusting I and Br content. The absorption onset for (NH 4 ) 3 Sb 2 I x Br 9− x films changes from 558 nm to 453 nm as x changes from 9 to 0. (NH 4 ) 3 Sb 2 I 9 single crystals were prepared, exhibiting a hole mobility of 4.8 cm 2 V −1 s −1 and an electron mobility of 12.3 cm 2 V −1 s −1 . (NH 4 ) 3 Sb 2 I 9 solar cells gave an open‐circuit voltage of 1.03 V and a power conversion efficiency of 0.51 %.