Enhanced optoelectronic performance and photogating effect in quasi-one-dimensional BiSeI wires

TL;DR

This study demonstrates that exfoliated quasi-1D BiSeI wires exhibit significantly enhanced optoelectronic performance, including ultrahigh responsivity and detectivity, primarily due to increased surface area and photogating effects, advancing low-dimensional photodetector technology.

Contribution

The paper reports the fabrication and testing of quasi-1D BiSeI wire-based photodetectors with superior performance, highlighting the role of surface effects and trapping states in enhancing optoelectronic properties.

Findings

Ultrahigh responsivity of 7 x 10^4 A/W

Specific detectivity of 2.5 x 10^{14} Jones

Enhanced quantum efficiency due to photogating

Abstract

Quasi-one-dimensional (quasi-1D) materials are a newly arising topic in low-dimensional researches. As a result of reduced dimensionality and enhanced anisotropy, the quasi-1D structure gives rise to novel properties and promising applications such as photodetectors. However, it remains an open question whether performance crossover will occur when the channel material is downsized. Here we report on the fabrication and testing of photodetectors based on exfoliated quasi-1D BiSeI thin wires. Compared with the device on bulk crystal, a significantly enhanced photoresponse is observed, which is manifested by a series of performance parameters, including ultrahigh responsivity (7 x 10$^4$ A W$^{-1}$), specific detectivity (2.5 x 10$^{14}$ Jones) and external quantum efficiency (1.8 x 10$^7$%) when $V_{\textrm {ds}}$ = 3 V, $\lambda$ = 515 nm and $P$ = 0.01 mW cm$^{-2}$. The conventional photoconductive effect is unlikely to account for such a superior photoresponse, which is ultimately understood in terms of the increased specific surface area and the photogating effect caused by trapping states. This work provides a perspective for the modulation of optoelectronic properties and performance in quasi-1D materials.