Direct Synthesis of MoSe2 Thin Films on SiO2/Si Using Selenization Process of Sputtered Molybdenum

Abstract

Recently, molybdenum diselenide (MoSe2) has attracted nascent research attention for potential applications in electronic and optoelectronic devices due to its unique properties including tunable bandgap, strong photoluminescence and large exciton binding energy. However, the synthesis of reproducible, controlled and large scale MoSe2 films is still a great challenge. Here, we have investigated the morphology, structure and crystalline quality of MoSe2 films synthesized by the selenization of Mo metal films. The Mo metal films of different thicknesses were deposited at room temperature by direct current sputtering. Subsequently, MoSe2 films were prepared by selenization of sputtered Mo films at 550 °C for 20 minutes. The obtained MoSe2 films are polycrystalline with hexagonal crystal structure. The crystalline quality of the MoSe2 films is improved with increase in the thickness of Mo metal films. The MoSe2 films are found to be n-type in nature and reasonably stoichiometric (Mo/Se ratio ∼1:1.9). This study provides an experimental demonstration of an alternative cost-effective direct synthesis of MoSe2 films on SiO2/Si for the applications of semiconductor devices.