Functionalized Molybdenum Disulfide Nanosheets for 0D–2D Hybrid Nanostructures: Photoinduced Charge Transfer and Enhanced Photoresponse

Abstract

The high-concentration stable dispersion of free-standing mono- or few-layer transition metal dichalcogenide (TMD) nanosheets (NSs) remains a significant barrier for their application in solution-processed optoelectronic devices. Here, we report oleylamine (OLA)- and dodecanethiol (DDT)-assisted exfoliation of MoS 2 NSs in nonpolar organic solvent 1,2-dichlorobenzene (DCB), which enables high-concentration stable dispersion of free-standing mono- or few-layer NSs. The functionalized MoS 2 NSs were further utilized for the fabrication of solution-processed 0D–2D hybrids of CuInS 2 quantum dots (CIS QDs) and MoS 2 NSs. The strong photoluminescence (PL) quenching and decreased PL lifetimes of CIS QDs attached to MoS 2 NSs indicates efficient charge transfer from photoexcited CIS to MoS 2 NSs. The photocurrent of CIS/MoS 2 hybrid devices is dramatically enhanced compared to that of pure CIS and pristine MoS 2 -based devices, confirming that efficient charge separation and transfer occur from CIS QDs to MoS 2 NSs.