Morphology-Controlled rGO−ZnO Nanostructures for Efficient Charge Transport and Visible Light Sensing via Schottky Junctions

Abstract

Abstract Two-dimensional graphene-based nanocomposites have emerged as promising materials for electronic and optoelectronic device applications. In this study, ZnO and reduced graphene oxide-ZnO (rGO−ZnO) nanocomposites were synthesized via a facile solvothermal approach. Their structural, morphological, and optical properties were systematically investigated using XRD, FT-IR, Raman spectroscopy, FE-SEM, TEM, XPS, and UV−visible spectroscopy. Furthermore, the visible-light photodetection performance of Schottky diodes fabricated using ZnO and rGO−ZnO nanocomposites is presented and analyzed. rGO−ZnO nanocomposites with ZnO exhibiting particle- and rod-like morphologies were prepared, and photodetectors were fabricated in the Schottky diode configuration. A comparative analysis of both photodetector and Schottky diode parameters was performed for the two nanostructured ZnO morphologies, with and without rGO incorporation. A substantial enhancement in photocurrent along with superior charge transport was achieved for the rGO−ZnO nanorod-based device. The origin of the photocurrent enhancement for the rGO−ZnO nanorod-based Schottky diode is systematically investigated through current−voltage (I−V) characteristics, time-dependent photocurrent studies, and their correlation with light absorption, morphology, and interfacial charge transport. These findings establish the effect of nanomaterial morphology and rGO on superior device performance and demonstrate that rGO−ZnO nanorods is a promising material for optoelectronic applications, including photovoltaic devices.