Design and optimization of high responsivity and detectivity of lead-free tin-based perovskite photodetectors by numerical simulation

Abstract

The low exciton binding energies, high optical absorption coefficients, narrow bandgaps, and non-toxicity make tin halide perovskites stand out as strong potentials for photodetectors (PDs). Here, three different narrow bandgap tin-based perovskites (MASnI₃, FASnI₃, and CsSnI₃) and six different wide bandgap n-type doped semiconductors (ZnO,TiO₂,SnO₂,ZnSe,WS₂ and CeO₂) were combined to construct heterojunction PDs, whose PD performance was predicted by SCAPS-1D. The thickness, doping concentration and defect density of the component layers were optimized to further reduce the carrier recombination losses and dark current densities to boost their performance. It reveals that the obtained Voc, Jsc and the maximum responsivity (R) are larger than 0.6 V, 24 mA/cm², and 0.4 A/W, respectively, while the maximum detectivity (D∗) reaches ∼10¹⁴ Jones. It demonstrates that the proposed environmentally friend PDs are hopeful to boost the performance of perovskite PDs and provide new ways for future perovskite PD designs and applications.