Harnessing Strong Band-Filling in Mixed Pb-Sn Perovskites Boosts the Performance of Concentrator-Type Photovoltaics

Abstract

The need for cutting-edge solar power generation has led to the rapid development of organic–inorganic hybrid perovskites with unique photophysical properties. Photoinduced band-filling by free charge carriers, which is a consequence of the dynamic filling of the densities of states, modulates the optical transition toward high energy. Here, we observe strong band-filling in FA0.5MA0.5­Pb0.5­Sn0.5I3 polycrystalline films under continuous-wave excitation, which is much more evident than that in typical MAPbI3. Inspired by this fact, we propose novel electronic barrier adaptive concentrator-type photovoltaics, achieved by inserting an electronic barrier-inducing indene-C60 bisadduct layer (ICBA). Under concentrated illumination, the potential barrier between FA0.5MA0.5­Pb0.5­Sn0.5I3 and ICBA remarkably decreases, leading to a greater fill factor and a higher power conversion efficiency of 17.0% compared to that (15.6%) of the reference device. Our results provide a proof-of-concept demonstration of a novel photovoltaic system using the photophysical property of perovskites.

Long-Lived Hot Carriers in Two-Dimensional Perovskites: The Role of Alternating Cations in Interlayer Space

“…Harvesting the excess energies of hot carriers before they are lost as heat − can potentially improve the power conversion efficiencies (PCEs) to exceed the conventional Shockley–Queisser limit and reach ∼66% theoretically under 1 sun illumination. − In traditional bulk semiconductors, hot carriers rapidly lose their energy after carrier–carrier scattering and interacting with phonons, resulting in an ultrashort HC cooling time (tens of femtoseconds at low carrier density). , To develop feasible and practical hot-carrier solar cells, the challenge lies in finding suitable solar absorbers that can achieve slow HC cooling and efficient HC extraction. In recent years, organic–inorganic hybrid perovskites have shown potential as hot-carrier light-harvesting materials − due to their facile synthesis, tunable optical properties, and excellent solar cell device performance. − In particular, highly stable two-dimensional (2D) hybrid perovskites offer intriguing possibilities for exploring hot-carrier-based optoelectronic and spintronic devices, as the nature of tunable quantum and dielectric confinement in these materials can decelerate the hot-carrier cooling rate. − While notable advancements have been made in the domain of 2D perovskites, challenges remain in achieving a high hot-carrier temperature and long hot carrier lifetime at a reasonable carrier density.…”