Pseudohalide‐Induced Moisture Tolerance in Perovskite CH 3 NH 3 Pb(SCN) 2 I Thin Films

Two pseudohalide thiocyanate ions (SCN − ) have been used to replace two iodides in CH 3 NH 3 PbI 3 , and the resulting perovskite material was used as the active material in solar cells. In accelerated stability tests, the CH 3 NH 3 Pb(SCN) 2 I perovskite films were shown to be superior to the conventional CH 3 NH 3 PbI 3 films as no significant degradation was observed after the film had been exposed to air with a relative humidity of 95 % for over four hours, whereas CH 3 NH 3 PbI 3 films degraded in less than 1.5 hours. Solar cells based on CH 3 NH 3 Pb(SCN) 2 I thin films exhibited an efficiency of 8.3 %, which is comparable to that of CH 3 NH 3 PbI 3 based cells fabricated in the same way.