Boosting the stability of fully-inorganic perovskite solar cells through samarium doped CsPbI₂Br perovskite

Fully inorganic cesium-lead halide (CsPbI2Br) perovskite is growing favorable to be promising alternative light-absorbing material to the organic-inorganic hybrid perovskite because of the boosted efficiency and stability of perovskite solar cells (PVSC). Nonetheless, the unsolved issue is still going on for the phase stability in ambient conditions. In this work, we employed the samarium (Sm3+) cation as a dopant as well as grain boundary passivating perovskite by a simple hot air method for inorganic perovskite solar cells (IPVSC). The CsPbI2Br with the optimal Sm3+ doping based IPVSC devices exhibited a peak power conversion efficiency (PCE) of 15.68% which is quite higher than the controlled device (12.85%). Our optoelectronic analysis revealed that the 3% Sm-CsPbI2Br perovskite film enabling the increased light-harvesting ability and higher charge transporting properties. Besides, our nonencapsulated a champion device containing Sm3+ cation doping retain >85% initial efficiency over 200 h under 85 °C stress. This work delivers a new approach to boost IPVSC photovoltaic performance.