Photoresponse improvement in liquid-exfoliated SnSe nanosheets by reduced graphene oxide hybridization

Abstract

The SnSe/reduced graphene oxide (SnSe/RGO) hybrid was synthesized by a simple hydrothermal reduction method using tin selenide (SnSe) nanosheets (NSs) and graphene oxide (GO), in which the two-dimensional SnSe NSs were peeled off by hydrothermal intercalation and exfoliation process, and GO was synthesized through an improved Hummers’ method. The characterization techniques including scanning electron microscopy and transmission electron microscopy verified a large-size SnSe NSs and SnSe/RGO hybrid. Meanwhile, X-ray diffraction and Raman spectra were carried out and confirmed the inherent optical and physical properties of SnSe NSs. In addition, the photoelectrochemical tests were carried out and proved that the photoresponse performances of as-prepared SnSe/RGO hybrid were greatly improved compared to that of sole SnSe NSs. When the bias potential was 0.8 V, the photocurrent density of SnSe/RGO hybrid was about 6.42 μA/cm2, which was approximately four times that of sole SnSe NSs (about 1.58 μA/cm2). Meanwhile, SnSe/RGO hybrid possessed faster photoresponse compared to sole SnSe NSs. The improvement in photoresponse performance is due to the hybridization of SnSe/RGO with good conductivity and the coupling between SnSe/RGO and SnSe NSs, which would be beneficial to promote the effective separation of photo-generated electron–hole pairs. Our results show that SnSe/RGO hybrid has a good application prospect in the field of photodetection.