Optoelectronic performance of multilayer WSe2 transistors enhanced by defect engineering

The presence of defects leads to a significant impact on the optical and electrical properties of TMDCs. The photoelectric performance of TMDCs can be tailored through defect engineering. In this work, we study defect engineering by using controlled annealing in air as an approach to improve the performance of photodetector based on multilayer WSe2. The responsivity and EQE of WSe2 photodetector show an obvious improvement after annealing. Furthermore, the photodetector displays a fast response on the order of tens of ms after annealing. The enhanced performance of the photodetector can be attributed to defect trapping and photogating effect.