Synthesis and photoelectric properties of nanometer size Mg0.2Zn0.8O films

MgZnO as a type of wide band-gap semiconductor has become a vital studied orientation in Ultraviolet (UV) detector. Nanometer size Mg0.2Zn0.8O films with homogeneous particle distribution were synthesized by sol-gel method and a wide UV respective photo-detector covered solar blind to near UV range has been obtained. The structure, surface morphology and properties of Mg0.2Zn0.8O films and photo-electric properties of detector have been studied. The thin film exhibits a strong (002) orientation growth property and all the Mg2+ ions have entranced into ZnO lattice. The average crystalline size of film is 30 nm and close to 70% particle size is between 25 nm and 35 nm. The films display a high transmittance close to 70%. The Eg of the film is 3.47 eV corresponding to absorption edge begins to 357 nm and the first exciton absorptive peak is at 346 nm. At various wavelength light illumination, the photo-detector with a simple metal/semiconductor/metal (MSM) structure shows a linear I-V relation. The spectral response is a broad band around between 250 nm and 400 nm peaking at 336 nm. The good responsivity arrives to 0.55 A/W, which is more than other reports.