 Lead-free double perovskites are a promising alternative to traditional solar cells due to their unique properties such as thermodynamic stability, appropriate band gaps, small carrier effective masses, and low exciton binding energies. Despite this, no solar cells based on these materials have yet been reported due to the difficulty in producing them. A new solar cell based on a lead-free double perovskite was recently developed using a low pressure assisted solution process under ambient conditions. This resulted in a high quality CS2 AG by BR6 film which presented a power conversion efficiency of 1.44%, demonstrating the potential of lead-free perovskite solar cells. Furthermore, the stability of the device under ambient conditions without encapsulation suggests great promise for lead-free perovskite solar cells. This article was authored by Tsu and Tsu-an-Wu, Xiaowei Zhang, Yang Lu, and others.