Superior visible photoelectric response with Au/Cu2NiSnS4 core-shell nanocrystals

TL;DR

This paper reports the synthesis of Au/Cu2NiSnS4 core-shell nanocrystals that significantly enhance visible light photoresponse through plasmonic effects, leading to improved photodetector performance.

Contribution

It introduces a novel colloidal hot-injection synthesis method for Au/CNTS core-shell nanocrystals with controlled properties, achieving superior optoelectronic response.

Findings

Enhanced optical absorption and carrier extraction in Au/CNTS structures

Significant increase in carrier density due to plasmonic resonance energy transfer

Outperforms traditional CNTS-based photodetectors

Abstract

The incorporation of plasmonic metal nanostructures into semiconducting chalcogenides, in the form of core-shell structures, represents a promising approach to boosting the performance of photodetectors. In this study, we combined Au nanoparticles with newly developed copper-based chalcogenides Cu2NiSnS4 (Au/CNTS), to achieve an ultrahigh optoelectronic response in the visible regime. The high-quality Au/CNTS core-shell structure was synthesized by developing a unique colloidal hot-injection method, which allowed excellent control over sizes, shapes, and elemental compositions. The fabricated Au/CNTS hybrid core-shell structure exhibited enhanced optical absorption, carrier extraction efficiency, and improved photo-sensing performance, owing to the plasmonic-induced resonance energy transfer effect of the Au core. This effect led to a significant increase in carrier density between the Au core and CNTS shell. These values outperformed a CNTS-based gate-free visible photodetector.