We present the influences of rare earth element Eu 3 + doping on the photoelectric characteristics of molybdenum disulfide ( MoS 2 ) films deposited on p-Si substrates using vapor deposition method. The surface topography, crystalline structure, light absorption, and luminescence properties of Eu 3 + doped and undoped MoS 2 thin films were investigated in detail. We found that the Eu 3 + doped MoS 2 films have better crystallinity, and their electron mobility and conductivity are approximately one order of magnitude higher than those of the undoped films. In addition, we observed that the light absorption and photoluminescence intensities of the doped films in the visible light range, they were enhanced by approximately two orders of magnitude than those of the undoped MoS 2 films at room temperature. Moreover, we found that the photoelectric response characteristics of the doped MoS 2 ∕ Si heterojunction improved significantly. The results show that the Eu 3 + doped MoS 2 films can be used to fabricate high efficiency luminescent and optoelectronic devices.