Hole transport enhancement of solution-processed MoS2 van der Waals thin-film transistors via DDQ enables high-performance photodetector

Abstract

Solution-processed MoS 2 thin films offer unique advantages such as low cost, large-area scalability, and process compatibility, making them well-established for achieving high-electron-mobility devices. Nevertheless, the lack of controllable doping and the notably poor hole-transport performance persist as critical challenges that must be resolved for their future device integration. In this study, we employ the oxidative molecule 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) to modulate the electrical properties of MoS 2 van der Waals (vdW) thin-film transistors (TFTs) and enhance hole conduction. DDQ can improve the energy level alignment with the Au electrode by increasing the work function of MoS 2 , increase the hole concentration, and passivate trap states between the nanosheets via the introduced carriers. Consequently, after DDQ modification, the hole mobility of MoS 2 TFTs increases from 6.9 × 10 -3 to 1.72 × 10 -1 cm 2 V -1 s -1 . For etched devices, the mobility rises from 4.4 × 10 -2 to 8.7 × 10 -1 cm 2 V -1 s -1 . More importantly, DDQ-doped MoS 2 vdW thin film photodetectors exhibit higher responsivity and detectivity compared to pristine devices. This work provides an innovative pathway toward broader application of solution-processed MoS 2 in electronic and optoelectronic devices.