基于第一性原理的掺杂单层WS2的光电效应

基于非平衡态格林函数-密度泛函理论,采用第一性原理方法,计算了VA族元素(N、P、As或Sb)掺杂单层WS2的光电效应,并解释了掺杂提高光电效应的微观机理.结果表明:在线性极化光照射下,单层WS2中可以产生光电流.由于掺杂降低了单层WS2的空间反演对称性,导致N、P、As或Sb分别掺杂的单层WS2的光照中心区产生的光电...

Photogalvanic Effect of Doped Monolayer WS2 Based on First-Principles

Based on the non-equilibrium Green function-density functional theory, the photoelectric effect of doped monolayer WS₂ with VA group elements (N, P, As or Sb) was calculated by first-principles, and the microcosmic mechanism of doping to improve the photogalvanic effect was explained. The results show that photocurrent can be generated in the monolayer WS₂ under linearly polarized light. Since the doping reduces the spatial inversion symmetry of the monolayer WS₂, the photocurrent generated by the illuminated central area of the monolayer WS₂ doped with N, P, As, or Sb significantly increases, and the photocurrent and the polarization angle show a perfect sinusoidal relationship, which conforms to the phenomenological theory. Among them, the effect of N doping is the best. The doped monolayer WS₂ obtains the maximum photocurrent (1.75) when the photon energy is 3.1 eV, and the polarization sensitivity reaches the maximum (18.1). The monolayer WS₂ doped with P, As and Sb achieves a larger photocurrent when the photon energy is 3.9 eV, and has a higher polarization sensitivity. The research results show that the doping can effectively enhance the photogalvanic effect and obtain higher polarization sensitivity, revealing the potential application prospects of doped monolayer.