MoTe<sub>2</sub> p–n Homojunctions Defined by Ferroelectric Polarization
Guangjian Wu, Xudong Wang, Yan Chen, Shuaiqin Wu, Binmin Wu, Yiyang Jiang, Hong Shen, Tie Lin, Qi Liu, Xinran Wang, Peng Zhou, Shan‐Tao Zhang, Weida Hu, Xiangjian Meng, Junhao Chu, Jianlu Wang
Abstract
Abstract Doped p–n junctions are fundamental electrical components in modern electronics and optoelectronics. Due to the development of device miniaturization, the emergence of two‐dimensional (2D) materials may initiate the next technological leap toward the post‐Moore era owing to their unique structures and physical properties. The purpose of fabricating 2D p–n junctions has fueled many carrier‐type modulation methods, such as electrostatic doping, surface modification, and element intercalation. Here, by using the nonvolatile ferroelectric field polarized in the opposite direction, efficient carrier modulation in ambipolar molybdenum telluride (MoTe 2 ) to form a p–n homojunction at the domain wall is demonstrated. The nonvolatile MoTe 2 p–n junction can be converted to n–p, n–n, and p–p configurations by external gate voltage pulses. Both rectifier diodes exhibited excellent rectifying characteristics with a current on/off ratio of 5 × 10 5 . As a photodetector/photovoltaic, the device presents responsivity of 5 A W −1 , external quantum efficiency of 40%, specific detectivity of 3 × 10 12 Jones, fast response time of 30 µs, and power conversion efficiency of 2.5% without any bias or gate voltages. The MoTe 2 p–n junction presents an obvious short‐wavelength infrared photoresponse at room temperature, complementing the current infrared photodetectors with the inadequacies of complementary metal‐oxide‐semiconductor incompatibility and cryogenic operation temperature.