Friction behavior of monolayer molybdenum diselenide nanosheet under normal electric field

The friction behavior of monolayer molybdenum diselenide (MoSe2) under normal electric field was studied by the atomic force microscope. The friction coefficients of MoSe2 are increasing with bias voltage applied on the Si substrate. The results show that the adhesion and electrostatic forces increase with bias and approximately follow a parabolic law. The friction force and surface potential are of the same tendency with bias application time, and the contribution of charges accumulation to friction is considerable. The mechanisms of the friction behavior under external normal electric field were explained with electrostatic force and adsorption. This study reveals a possibility of electronically controlling friction in two-dimensional MoSe2 system, with potential applications in solid lubricant and moving parts for MEMS devices.