Growth of Multilayer WSe<sub>2</sub>/Bi<sub>2</sub>O<sub>2</sub>Se Heterostructures for Photodetection without Lithography
Jun-Cheol Park, Seung‐Kyu Kim, Hojoong Choi, Yoonsung Jung, Inhyeok Oh, Jun Beom Hwang, Sanghan Lee
Abstract
Novel oxychalcogenides, such as Bi 2 O 2 Se, have many applications because of their interesting properties such as remarkable hall mobility, the presence of a bandgap, and high air stability. Among them, photodetectors based on Bi 2 O 2 Se are one of the best applicable devices. In addition, the Bi 2 O 2 Se heterostructure with other 2D materials can enhance the photoresponse of the device. In this study, we successfully fabricated the WSe 2 /Bi 2 O 2 Se heterostructure for photodetector application via in situ pulsed laser deposition. The band alignment of the as-grown WSe 2 /Bi 2 O 2 Se heterostructure was confirmed to be type II, which increases the photoresponse. Furthermore, the WSe 2 /Bi 2 O 2 Se photodetector exhibited an approximately 110% on/off ratio with a photoresponsivity of 0.96 mA/W even without using lithography for its fabrication.