Metal halide perovskite materials with the general structure of ABX3 (A = Cs+, CH3NH3+ (MA+, methylammonium), or CH(NH2)2+ (FA+, formamidinium); B = Pb2+ or Sn2+; X = Cl−, Br−, or I−) have garnered considerable attention for applications in light-emitting devices, lasing, sensors, smart windows, photodetectors, and solar cells owing to their superior optoelectronic properties, such as appropriate bandgap, high optical absorption coefficient long carrier lifetime, long carrier diffusion length, and low exciton binding energy. In particular, perovskite solar cells (PSCs) are considered as the most promising next-generation photovoltaic (PV) devices owing to their low-cost fabrication and outstanding performance. The main challenge in the future commercialization of PSCs is the further improvement of perovskite materials to achieve superior PCE and excellent stability under ambient environmental conditions.

(a) 3D render overlay images of In (b) 3D render overlay images of Pb (c) ToF-SIMS spectra of device (d) TRPL spectra of different perovskite films.

In this study, we demonstrate that a small amount of indium (In3+) ions in mixed cation and halide perovskites can effectively passivate the defects, improve the energy-level alignment, and reduce the exciton binding energy. Additionally, we confirmed that In3+ ions can significantly elevate the initial carrier temperature, slow down the hot-carrier cooling rate, and reduce the heat loss before carrier extraction. The device with 1.5% of incorporated In3+ achieved a PCE of 22.4% with a negligible hysteresis, which is significantly higher than that of undoped PSCs (20.3%). In addition, the unencapsulated PSCs achieved long-term stability, which retained 85% of the original PCE after 3,000 h of aging in dry air. The obtained results demonstrate and promote the development of practical, highly efficient, and stable hot-carrier-enhanced PSCs.

This research is published by "Chaocheng Zhou, Tianju Zhang, Chao Zhang, Xiaolin Liu, Jun Wang, Jia Lin, Xianfeng Chen, Unveiling Charge Carrier Recombination, Extraction, and Hot-Carrier Dynamics in Indium Incorporated Highly Efficient and Stable Perovskite Solar Cells, Advanced Science, 2103491(2022)”.

Link: https://onlinelibrary.wiley.com/doi/10.1002/advs.202103491