Modulating Electronic Structure of Monolayer Transition Metal Dichalcogenides by Substitutional Nb‐Doping
Lei Tang, Runzhang Xu, Junyang Tan, Yuting Luo, Jingyun Zou, Zongteng Zhang, Rongjie Zhang, Yue Zhao, Junhao Lin, Xiaolong Zou, Bilu Liu, Hui‐Ming Cheng
Abstract
Abstract Modulating electronic structure of monolayer transition metal dichalcogenides (TMDCs) is important for many applications, and doping is an effective way toward this goal, yet is challenging to control. Here, the in situ substitutional doping of niobium (Nb) into TMDCs with tunable concentrations during chemical vapor deposition is reported. Taking monolayer WS 2 as an example, doping Nb into its lattice leads to bandgap changes in the range of 1.98–1.65 eV. Noteworthy, electrical transport measurements and density functional theory calculations show that the 4d electron orbitals of the Nb dopants contribute to the density of states of Nb‐doped WS 2 around the Fermi level, resulting in an n‐ to p‐type conversion. Nb‐doping also reduces the energy barrier of hydrogen absorption in WS 2 , leading to an improved electrocatalytic hydrogen evolution performance. These results highlight the effectiveness of controlled doping in modulating the electronic structure of TMDCs and their use in electronic related applications.