Electrical contacts for high performance optoelectronic devices of BaZrS3 single crystals

TL;DR

This paper develops electrical contact fabrication methods for BaZrS3 single crystals, overcoming surface dielectric challenges, and demonstrates high-performance photoconductive devices with low dark current and fast response.

Contribution

It introduces optimized dry etching processes for electrical contacts on BaZrS3 single crystals, enabling high-quality optoelectronic device performance.

Findings

Low dark current of 0.1 nA at 10 V bias

Fast transient photoresponse with <0.2 s rise and decay time

Successful fabrication of high-performance photoconductive devices

Abstract

Chalcogenide perovskites such as BaZrS3 are promising candidates for next generation optoelectronics such as photodetectors and solar cells. Compared to widely studied polycrystalline thin films, single crystals of BaZrS3 with minimal extended and point defects, are ideal platform to study the material's intrinsic transport properties and to make first-generation optoelectronic devices. However, the surface dielectrics formed on BaZrS3 single crystals due to sulfating or oxidation have led to significant challenges to achieving high quality electrical contacts, and hence, realizing the high-performance optoelectronic devices. Here, we report the development of electrical contact fabrication processes on BaZrS3 single crystals, where various processes were employed to address the surface dielectric issue. Moreover, with optimized electrical contacts fabricated through dry etching, high-performance BaZrS3 photoconductive devices with a low dark current of 0.1 nA at 10 V bias and a fast transient photoresponse with rise and decay time of <0.2 s were demonstrated.