Controllable p-type doping and improved conductance of few-layer WSe2via Lewis acid.

Manipulation of the electronic properties of layered transition-metal dichalcogenides (TMDs) is of fundamental significance for a wide range of electronic and optoelectronic applications. Surface charge transfer doping is considered to be a powerful technique to regulate the carrier density of TMDs. Herein, the controllable p-type surface modification of few-layer WSe₂by FeCl₃Lewis acid with different doping concentrations have been achieved. Effective hole doping of WSe₂has been demonstrated using Raman spectra and XPS. Transport properties indicated the p-type FeCl₃surface functionalization significantly increased the hole concentration with 1.2 × 10¹³cm^-2, resulting in 6 orders of magnitude improvement for the conductance of FeCl₃-modified WSe₂compared with pristine WSe₂. This work provides a promising approach and facilitate the further advancement of TMDs in electronic and optoelectronic applications.