Controllable p-type doping and improved conductance of few-layer WSe 2 via 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 WSe 2 by FeCl 3 Lewis acid with different doping concentrations have been achieved. Effective hole doping of WSe 2 has been demonstrated using Raman spectra and XPS. Transport properties indicated the p-type FeCl 3 surface functionalization significantly increased the hole concentration with 1.2 × 10 13 cm −2 , resulting in 6 orders of magnitude improvement for the conductance of FeCl 3 -modified WSe 2 compared with pristine WSe 2 . This work provides a promising approach and facilitate the further advancement of TMDs in electronic and optoelectronic applications.