Recently, the development of lead‐free perovskite solar cells has attracted considerable attention. However, in tin halide perovskites, Sn 2+ is prone to be oxidized to Sn 4+ , which leads to the occurrence of p‐type self‐doping in the perovskite, high defect density, and nonradiative recombination, thus severely restricting the open‐circuit voltage ( V oc ) and efficiency. To address this, 6‐thioguanine (TG) and 2‐aminopurine (2‐AP) were introduced into the perovskite precursor. The experimental results showed that the V oc of the target device with TG has significantly increased from 0.80 to 0.92 V, and the power conversion efficiency (PCE) has also risen from 11.04% to 13.84%. In addition, the TG device can maintain approximately 87% of their initial PCE after being stored in an N 2 atmosphere for 1400 h. This work provides an effective approach to simultaneously enhance the performance and stability of tin halide perovskite solar cells through molecular coordination strategy.
Du et al. (Fri,) studied this question.