Giant renormalization of dopant impurity levels in 2D semiconductor MoS2

Jeongwoon Hwang; Chenxi Zhang; Yong-Sung Kim; Robert M Wallace; Kyeongjae Cho

doi:10.1038/s41598-020-61675-y

Giant renormalization of dopant impurity levels in 2D semiconductor MoS₂

Sci Rep. 2020 Mar 18;10(1):4938. doi: 10.1038/s41598-020-61675-y.

Authors

Jeongwoon Hwang^{1

2}, Chenxi Zhang¹, Yong-Sung Kim³, Robert M Wallace¹, Kyeongjae Cho⁴

Affiliations

¹ Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas, 75080, USA.
² Department of Physics Education, Chonnam National University, Gwangju, 61186, Korea.
³ Korea Research Institute of Standards and Science, Yuseong, Daejeon, 305-340, Korea.
⁴ Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas, 75080, USA. kjcho@utdallas.edu.

Abstract

Substitutional doping in 2D semiconductor MoS₂ was investigated by charge transition level (CTL) calculations for Nitrogen group (N, P, As, Sb) and Halogen group (F, Cl, Br, I) dopants at the S site of monolayer MoS₂. Both n-type and p-type dopant levels are calculated to be deep mid-gap states (~1 eV from band edges) from DFT total energy-based CTL and separate DFT + GW calculations. The deep dopant levels result from the giant renormalization of hydrogen-like defect states by reduced dielectric screening in ultrathin 2D films. Theoretical analysis based on Keldysh formulation provides a consistent impurity binding energy of ~1 eV for dielectric thin films. These findings of intrinsic deep impurity levels in 2D semiconductors MoS₂ may be applicable to diverse novel emerging device applications.