Ultrahigh photoresponse of few-layer TiS3 nanoribbon transistors

TL;DR

This paper demonstrates that few-layer TiS3 nanoribbon transistors exhibit ultrahigh photoresponse and fast response times, making them highly effective nanoscale photodetectors across the visible spectrum.

Contribution

It introduces the fabrication and characterization of TiS3 nanoribbon transistors with exceptional optoelectronic performance, a largely unexplored material in this context.

Findings

Photoresponse of 2910 A/W under illumination

Mobility up to 2.6 cm^2/Vs and ON/OFF ratio of 10^4

Cutoff frequency up to 1000 Hz

Abstract

Here, we isolate thin TiS3 ribbons, a layered direct band gap semiconductor (1.1 eV, well suited for detection all across the visible spectrum), thus far almost unexplored. We fabricate field effect transistors and study their electrical characteristics and optoelectronic properties. The measured FET characteristics show mobilities up to 2.6 cm^2/Vs and ON/OFF ratios up to 10^4. Under illumination, the TiS3 NR-FETs present an ultrahigh photoresponse of 2910 A/W and fast rise/fall times of ~4 ms. In addition, we measure cutoff frequencies (f3dB) up to 1000 Hz. The strong combination of ultrahigh sensitivity all along the visible spectrum and fast time response of TiS3 nanoribbon transistors put them among the best nanoscale photodetectors to date.