Marked Near-Infrared Response of 2D Ca3Sn2S7 Chalcogenide Perovskite via Solid and Electronic Structure Engineering

Developing high-performance photodetectors relies on the continuous innovation of photoelectric conversion materials. Here, we theoretically study a newly proposed photoelectric material based on the graphene-like two-dimensional (2D) Ca3Sn2S7 chalcogenide perovskite by employing the macroscopic continuum device (MCD) model and the Shockley-Queisser limit (SQM) model. Based on these key properties quantum mechanically calculated, we compared the photoelectric response of Ca3Sn2S7 perovskites by evaluating the dependence of photocurrents of different layered Ca3Sn2S7 perovskites with film thicknesses and charge recombination rates (different recombination mechanisms). The optimized photocurrent losses from MCD simulations are smaller than 5% compared to the SQM currents, while the charge lifetime is longer than 10-8 s and the bimolecular recombination rate constant is less than 1.0 x 10(-15) m(3)/s. Considering these effective measures to tune the charge recombination rates in experiments, our simulations predict superior IR detection performance when Ca3Sn2S7 is used in a photodetector device based on the spectral short-circuit currents per unit wavelength. As a comparison, we further simulate the photoelectric performance of 2D phosphorene and tellurene and elucidate that the photocurrent losses of Ca3Sn2S7 perovskites are smaller as a result of higher mobilities.

Automated summary

By comparing the performance of Ca3Sn2S7 photovoltaic materials with different thicknesses and charge recombination rates, it was found that the optimized photocurrent losses are less than 5%, the charge lifetime is longer than 10-8 seconds, and the bimolecular recombination rate constant is less than 1.0 x 10(-15) m(3)/s. Through effective measures to adjust the charge recombination rates in experiments, simulations suggest superior infrared detection performance when Ca3Sn2S7 is used in a photodetector device based on short-circuit currents per unit wavelength.