Enhanced Photocarrier Generation with Selectable Wavelengths by M-Decorated-CuInS Nanocrystals (M = Au and Pt) Synthesized in a Single Surfactant Process on MoS Bilayers.

A facile approach for the synthesis of Au- and Pt-decorated CuInS nanocrystals (CIS NCs) as sensitizer materials on the top of MoS bilayers is demonstrated. A single surfactant (oleylamine) is used to prepare such heterostructured noble metal decorated CIS NCs from the pristine CIS. Such a feasible way to synthesize heterostructured noble metal decorated CIS NCs from the single surfactant can stimulate the development of the functionalized heterostructured NCs in large scale for practical applications such as solar cells and photodetectors. Photodetectors based on MoS bilayers with the synthesized nanocrystals display enhanced photocurrent, almost 20-40 times higher responsivity and the On/Off ratio is enlarged one order of magnitude compared with the pristine MoS bilayers-based photodetectors. Remarkably, by using Pt- or Au-decorated CIS NCs, the photocurrent enhancement of MoS photodetectors can be tuned between blue (405 nm) to green (532 nm). The strategy described here acts as a perspective to significantly improve the performance of MoS -based photodetectors with the controllable absorption wavelengths in the visible light range, showing the feasibility of the possible color detection.