Enhancing the photo-response performance of a SnSe-based photoelectrochemical photodetector via Ga doping

Abstract

Layered SnSe in nanostructures has recently attracted growing interest in photonics, optoelectronics, photocatalysis, energy storage, and biomedicine because of its suitable band gap, excellent light absorption capacity, and considerable carrier mobility. However, the applications of SnSe in high-performance photoelectrochemical (PEC) devices are greatly hindered due to high-density defects, which lead to its high recombination of charge carriers and environmental instability. In this contribution, we have adopted a doping strategy to enhance the photo-response properties of a SnSe-based PEC photodetector. The as-prepared Ga-doped SnSe nanostructure shows a remarkable increase in photocurrent density, stable on–off cyclicity, fast photo-response behavior, and higher specific detectivity compared to the pristine SnSe. Based on structure characterization, composition analysis, and DFT calculations, the substitution of Sn by Ga in the lattice gives rise to changes in the electronic structure and optical absorption, endowing Ga-doped SnSe with a metal-like feature. Such a doping strategy can provide fundamental support in the development of SnSe-based devices and pave the way for PEC applications.