Bidirectional rectifier with gate voltage control based on Bi<sub>2</sub>O<sub>2</sub>Se/WSe<sub>2</sub> heterojunction
Ruonan Li, Fangchao Lu, Jiajun Deng, Xingqiu Fu, Wenjie Wang, He Tian
Abstract
Abstract Two-dimensional (2D) WSe 2 has received increasing attention due to its unique optical properties and bipolar behavior. Several WSe 2 -based heterojunctions exhibit bidirectional rectification characteristics, but most devices have a lower rectification ratio. In this work, the Bi 2 O 2 Se/WSe 2 heterojunction prepared by us has a type Ⅱ band alignment, which can vastly suppress the channel current through the interface barrier so that the Bi 2 O 2 Se/WSe 2 heterojunction device has a large rectification ratio of about 10 5 . Meanwhile, under different gate voltage modulation, the current on/off ratio of the device changes by nearly five orders of magnitude, and the maximum current on/off ratio is expected to be achieved 10 6 . The photocurrent measurement reveals the behavior of recombination and space charge confinement, further verifying the bidirectional rectification behavior of heterojunctions, and it also exhibits excellent performance in light response. In the future, Bi 2 O 2 Se/WSe 2 heterojunction field-effect transistors have great potential to reduce the volume of integrated circuits as a bidirectional controlled switching device.