Improving the Photoelectric Characteristics of MoS(2) Thin Films by Doping Rare Earth Element Erbium

We investigated the surface morphologies, crystal structures, and optical characteristics of rare earth element erbium (Er)-doped MoS(2) (Er: MoS(2)) thin films fabricated on Si substrates via chemical vapor deposition (CVD). The surface mopography, crystalline structure, light absorption property, and the photoelectronic characteristics of the Er: MoS(2) films were studied. The results indicate that doping makes the crystallinity of MoS(2) films better than that of the undoped film. Meanwhile, the electron mobility and conductivity of the Er-doped MoS(2) films increase about one order of magnitude, and the current-voltage (I-V) and the photoelectric response characteristics of the Er:MoS(2)/Si heterojunction increase significantly. Moreover, Er-doped MoS(2) films exhibit strong light absorption and photoluminescence in the visible light range at room temperature; the intensity is enhanced by about twice that of the undoped film. The results indicate that the doping of MoS(2) with Er can significantly improve the photoelectric characteristics and can be used to fabricate highly efficient luminescence and optoelectronic devices.