Position dependent photodetector from large area reduced graphene oxide thin films

TL;DR

This study demonstrates a position-dependent infrared photodetector using large-area reduced graphene oxide films, where the photoresponse varies with laser position due to Schottky barrier effects, highlighting potential for spatially sensitive optoelectronic devices.

Contribution

It introduces a large-area RGO-based photodetector with position-sensitive response, explaining the effect through Schottky barrier modulation at the interface, and discusses the slow response due to synthesis disorder.

Findings

Photocurrent varies with laser position relative to electrodes.

Photoresponse is explained by Schottky barrier modulation.

Photocurrent response is slower than in pristine graphene.

Abstract

We fabricated large area infrared photodetector devices from thin film of chemically reduced graphene oxide (RGO) sheets and studied their photoresponse as a function of laser position. We found that the photocurrent either increases, decreases or remain almost zero depending upon the position of the laser spot with respect to the electrodes. The position sensitive photoresponse is explained by Schottky barrier modulation at the RGO film-electrode interface. The time response of the photocurrent is dramatically slower than single sheet of graphene possibly due to disorder from the chemically synthesis and interconnecting sheets.