Tuning the optical and electrical properties of MoS2 by selective Ag photo-reduction

Two-dimensional transition metal dichalcogenides have demonstrated potential for advanced electrical and optoelectronic applications. For these applications, it is necessary to modify their electrical or optoelectronic properties. Doping is one of the most prevalent techniques to modify the band structure of semiconductor materials. Herein, we report the p-type doping effect on few-layer and multi-layer MoS2 that are selectively decorated with Ag nanoparticles via laser-assisted direct photoexcitation of MoS2 exposed in AgNO3 solution. This method can control the doping level by varying the duration of the laser irradiation, which is confirmed by the observed gradual rise of MoS2 device channel resistance and photoluminescence spectra enhancement. This study demonstrated a simple, controllable, and selective doping technique using laser-assisted photo-reduction.