The enhanced photoelectric properties of ZnO-doped WSe2 thin film

The photoelectric properties of ZnO-doped WSe2 thin films created on Si substrates by a thermal evaporation method were investigated. The effects of ZnO on the surface morphology, structure, photoluminescence, light absorption characteristics and electrical properties of WSe2 thin films were analyzed. It is found that the nucleation density and the crystallinity of the ZnO-doped WSe2 nanowires are higher than without doping, and the electron mobility of the doped sample is about 1.4 times that of the undoped sample. Also, doping improved the light absorption and photoluminescence efficiency. Additionally, the I-V curve of the ZnO-doped WSe2/Si heterojunction gradually changes from a rectification characteristic to a linear dependence, and the photocurrent increases by about four times when the light power increases from 0 to 25 mW/cm(2). Moreover, the heterojunction has a very high sensitivity to operating temperature; the current significantly increases as the temperature increases to 300 degrees. With high absorptivity and photoluminescence efficiency, and sensitivity to light and temperature, ZnO-doped WSe2 film is promising for use in optoelectronic devices.