Single crystals of molybdenum-doped ReSe 2 have been grown by chemical vapor transport (CVT) process with Br 2 as a transporting agent. XRD has been used to confirm the triclinic-layered structure of the as-grown undoped and doped samples. The optical properties are studied by anisotropic photovoltage and electrolyte electroreflectance measurements at 300 K. Both indirect and direct transition energies of the doped samples all show different degrees of red shifts for molybdenum-doped samples. The broadening parameters of the excitonic transition features broadened significantly for Mo-doped ReSe 2 due to impurity scattering in layered structures. The electrical properties are investigated by the anisotropic conductivity and Hall measurements at 300 K. The influence of optical and electrical properties from the molybdenum dopant were compared and discussed.