Modulation of Semiconductor Doping of 2D GeSe in h-BN/GeSe van der Waals Heterostructure

Herein, a novel controllable and nondestructive semiconductor doping technique is proposed by introducing defects in the h-BN/GeSe van der Waals heterostructure. A perfect n-/p-type channel layer can be achieved through charge transfer between the defective h-BN substrate layer and the GeSe channel layer. The effect of this modulation doping strategy on the carrier mobility of the channel layers is also investigated. In the case of the h-BN/GeSe heterostructure with the introduction of boron vacancies, the electron mobility of 2D GeSe in the x (y) direction is 1479.11 (1343.95) cm² V^–1 s^–1, and the hole mobility in the x (y) direction is 1031.88 (864.44) cm² V^–1 s^–1. As for producing nitrogen vacancies in the h-BN/GeSe heterostructure, the electron mobility of 2D GeSe in the x (y) direction is predicted to be as high as 1643.77 (1678.14) cm² V^–1 s^–1, and the hole mobility in the x (y) direction is about 1129.51 (1563.50) cm² V^–1 s^–1, respectively. In contrast, the electron (hole) mobility in the x-direction is dramatically decreased to 705.29 (630.85) cm² V^–1 s^–1, and the electron (hole) mobility in the y-direction is only 701.40 (481.37) cm² V^–1 s^–1 for the GeSe layer by using the traditional semiconductor doping method. The nondestructive doping strategy provides an effective method to modulate two-dimensional semiconductor channel materials while avoiding lattice damage, thus resulting in much higher carrier mobility. It indicates that the novel semiconductor doping technique has a great promising application in electronic and optoelectronic devices.