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 MoS₂ 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 MoS₂ NSs were further utilized for the fabrication of solution-processed 0D-2D hybrids of CuInS₂ quantum dots (CIS QDs) and MoS₂ NSs. The strong photoluminescence (PL) quenching and decreased PL lifetimes of CIS QDs attached to MoS₂ NSs indicates efficient charge transfer from photoexcited CIS to MoS₂ NSs. The photocurrent of CIS/MoS₂ hybrid devices is dramatically enhanced compared to that of pure CIS and pristine MoS₂-based devices, confirming that efficient charge separation and transfer occur from CIS QDs to MoS₂ NSs.