High-Performance Sn-Based Quasi-Two-Dimensional Perovskite Photodetectors by Altering Dark Current Shunt Pathways

Abstract

Self-powered perovskite photodetectors (PDs) have been widely used in the fields of communications and imaging, but their performance is still restricted by the high dark current of devices. This study has shown that the dark current of PDs can be significantly reduced by adjusting the composition of the dark current shunting paths. We have fabricated a less toxic high-performance PDs based on two-dimensional tin-based perovskite BA2FASn2I7. By controlling the grain size of the perovskite film with potassium salt of hydroquinone sulfonic acid (KHQSA), we increased the number of horizontal shunting paths and the dark current was reduced to 1/50th of its original value. The device shows a high responsivity of 1.4 A W–1, a high detectivity of 8.2 × 1013 Jones, a maximum on/off current ratio of 6.74 × 105, and a rapid rise/decay time of 12.2/14 ms. In addition, as a light signal receiver in an imaging system, the device can accurately and sensitively identify light signals under weak light conditions. This study provides a new way for further improving the performance of self-powered perovskite PDs by adjusting the composition of horizontal and vertical dark current shunting paths.

Strategies for suppressing dark current of perovskite photodiodes towards reliable optoelectronic applications

“…This reduction in J d was attributed to the increased presence of shunting paths. 25 Furthermore, the inherently weaker halide-ion migration in the Sn-based material provides an advantage in suppressing J d . Similarly, Dey et al conducted an investigation using scan-rate-dependent hysteresis analyses, temperature-dependent impedance spectroscopy measurements, and first-principles calculations on mixed Pb–Sn MHPs.…”