As a result of redox reaction proceeding in the solid phase, the intercalated molybdenum diselenides were obtained in the form of polycrystalline thin films M0.5MoSe2, where M=Ga, In or T1. Surface images of these substances were presented and an X-ray analysis of the crystalline structure was carried out to determine the crystallographic system, the space group and the lattice constants. On investigation, the electrical properties proved the semiconducting character of these compounds and also the type of conductivity, the quantity of specific conductivity, the energy gap, and the activation energy of dopants were determined. The study of optical absorption was carried out in order to relate the absorption coefficient to the photon energy. The occurrence of the photoelectrical properties of the material obtained has been confirmed.