Frasca, C.; Alippi, P.; Schwiddessen, R.; Prashanthan, K.; Nasti, G.; Zuo, S.; Rehman, M.O.U.; Aldamasy, M.H.; Hartono, N.T.P.; Musiienko, A.; Abate, A.: Mitigation of Self-p-Doping and Off-Centering Effect in Tin Perovskite via Strontium Doping. ACS Energy Letters 10 (2024), p. 526-533
10.1021/acsenergylett.4c02974
Open Access Version
Abstract:
Tin-based perovskite solar cells offer a less toxic alternative to their lead-based counterparts. Despite their promising optoelectronic properties, their performances still lag behind, with the highest power conversion efficiencies reaching around 15%. This efficiency limitation arises primarily from electronic defects leading to self-p-doping and stereochemical activity of the Sn(II) ion, which distorts the atomic arrangement in the material. In this study, we investigate the effect of strontium doping in tin-based perovskite on the distortion of the material’s structure and its optoelectronic properties. Using a combination of Density Functional Theory calculations and experiments, we demonstrate that strontium doping reduces p-doping and structural strain. This approach improves the efficiency from 6.3% in undoped devices to 7.5% in doped devices without relying on dimethyl sulfoxide, a harmful solvent for tin-based perovskites. This method could enable precise control of tin off-centering and self-p-doping, advancing the development of efficient and stable tin perovskite solar cells.