Optoelectronic characterisation of twisted germanium sulfide nanowires with experimental observation of intrinsic ferroelectricity

TL;DR

This study demonstrates room-temperature ferroelectricity and high charge mobility in twisted germanium sulfide nanowires, highlighting their potential for advanced optoelectronic applications.

Contribution

First experimental observation of ferroelectricity in GeS nanowires and detailed optoelectronic characterization showing enhanced charge mobility.

Findings

Ferroelectric order observed at room temperature in GeS nanowires

Charge carrier mobility is up to two orders higher than in GeS nanosheets

Nanowires exhibit stable, robust photo-switching properties

Abstract

We report the optoelectrical characterisation of Eshelby twisted Germanium sulfide (GeS) nanowires with first experimental observation of ferroelectric order at room temperature in GeS which is an otherwise centrosymmetric molecule. The chemical composition and structure of these nanowires were confirmed by various spectroscopic, microscopic and diffractive techniques. In addition, the nanowires were found to be stable over time. From the optoelectronic measurements we found that these p-type semiconducting GeS nanowires have up to two orders higher charge carrier mobility than GeS nanosheets and have sustainable, robust photo-switching property. The existence of room temperature ferroelectricity is confirmed by piezoresponse force microscopy which showed hysteresis and butterfly loop, characteristics of a ferroelectric material. Our observations reveal that the properties of twisted GeS nanowires can be harnessed in making efficient electric sensors, photodetectors, data memories and flexible electronics.