The preparation and the photoelectric characteristics of graphene/MoSe₂ heterojunction

The paper presents the preparation and optoelectronics characteristics of grapheme/molybdenum selenide (MoSe₂) heterojunction.MoSe₂ films was deposited on Si substratesusing used MoSe₂ powder as a raw material by a chemical vapour deposition (CVD) method, and then the graphene/MoSe2 heterojunction was formed by grown a graphene layer on the MoSe₂ film using methane (CH₄) as a raw material. The prepared MoSe₂ films were consisted of many nanowires about 2 nm in diameter and 7 nm in length perpendicular to the surface observed by an Atomic force microscopy (AFM), while many small graphene pieces were formed and dispersed on MoSe₂ film surface. Additionally, we found that the growth of MoSe₂ film has a strong orientation growth in the (400) crystal plane, which consistent with the MoSe₂ film composed of many parallel nanowires in the AFM picture. Moreover, we found that the graphene/MoSe₂ heterojunction has good absorption properties for visible light and has a significant photocurrent generation under illumination, indicating that the graphene/MoSe₂ heterojunction has excellent optical and electrical properties and has great potential for application in the field of optoelectronic devices. (paper)