A new strategy to improve the performance of MoS2-based 2D photodetector by synergism of colloidal CuInS2 quantum dots and surface plasma resonance of noble metal nanoparticles

Owing to their extraordinary optoelectronic properties, 2D transition metal dichalcogenides (TMDs) are proved to be promising materials for photodetectors . However, they suffered from poor absorptivity due to their atomically thin profile. Herein, CuInS 2 quantum dots (QDs) and plasmonic Au nanoparticles (AuNPs) were adopted to achieve a MoS 2 -CuInS 2 -AuNPs 2D–0D hybrid by simultaneous deposition of CuInS 2 QDs and AuNPs on the MoS 2 nanosheet . In this configuration, MoS 2 is used as a high mobility carrier transport channel, while CuInS 2 QDs act as an efficient light absorber, and the AuNPs serve as a light sensitizer to enhance the local electric field around MoS 2 and CuInS 2 QDs via surface plasmon resonance (SPR). With such synergism of CuInS 2 QDs and Au NPs, the highest responsivity of 16.65 A W − 1 $16.65\mathrm{A}{W}^{-1}$ and D * as high as 2.27 × 10 12 Jones $2.27\times {10}^{12}\mathit{Jones}$ are achieved for the MoS 2 -CuInS 2 -AuNPs hybrid devices under 635 nm laser, which is two orders of magnitude higher than the pristine MoS 2 devices and outperformed most of the other MoS 2 -based photodetectors . Finally, the synergistic effect of the CuInS 2 QDs and Au nanoparticles is illustrated by Finite-Difference Time-domain(FDTD) simulation. The underlying synergism strategy for such a 2D–0D configuration may also be applied to other photo-electric devices.