High frequency permittivity of rare-earth Er-doped MoS2 films

Abstract

Two-dimensional (2D) MoS2 has attracted considerable attention for their significant potential application in high-frequency electronic devices. In this work, erbium doped MoS2 (Er:MoS2) film is prepared by chemical vapor deposition. The structures and binding energy are studied by X-ray photoelectron spectroscopy indicating the substitution of Er atoms into MoS2 lattices. The complex permittivity of the film is measured by the microstrip line up to the frequency of 4 GHz. The high frequency permittivity ε′ of MoS2 film is 4.11 and ε′ increases about 28% when the Er doping amount is 0.83 at% (atomic percentage). The permittivity of Er:MoS2 film is higher than that of MoS2 film, which is mainly due to the enhanced polarization of Er:MoS2 film. The permittivity ε′ of Er:MoS2 film increases with the increase of Er doping (0∼0.83 at%). It is believed that Er:MoS2 film has great potential application in tunable electromagnetic devices.