Customization of MoS2 Phototransistors via Thiol‐Based Functionalization

Abstract The thiol‐based functionalization of multilayer MoS 2 is performed to customize its electrical and optical performance. Two types of thiol‐terminated organic molecules are utilized: 4‐amino thiophenol (4ATP) for electron‐donating and 4‐nitro thiophenol (4NTP) for electron‐withdrawing. The thiol groups in these molecules chemically bond with MoS 2 at the sulfur vacancies through the simple solution process. 4ATP‐functionalized MoS 2 (4ATP–MoS 2 ) transistors exhibit a huge enhancement in the current and the carrier concentration, whereas 4NTP‐functionalized MoS 2 (4NTP–MoS 2 ) transistors show the reduction in the film conductance. Moreover, functionalization with 4ATP and 4NTP complementarily modulate the photoresponsive characteristics of MoS 2 transistors. Under 405 nm laser illumination, 4ATP–MoS 2 phototransistors exhibit the enhanced photoresponsivity of 669.10 A W −1 attributed to the large dark currents. In contrast, 4NTP–MoS 2 phototransistors can achieve faster photoswitching performances than 4ATP–MoS 2 . Therefore, the thiol‐based functionalization can effectively customize the electrical and optical characteristics of multilayer MoS 2 .