Fabrication of high-performance UV photodetector using gallium doped ZnO thin films by nebulizer spray pyrolysis method

The gallium doped zinc oxide (ZnO:Ga) thin films were produced using nebulizer spray pyrolysis technique (NSP) with glass substrate at 450 degrees C. The structure, surface, optical absorption, and UV photo-sensing properties were analyzed. All the films were confirmed to be polycrystalline having a hexagonal structure and a preferred orientation along c-axis by the XRD patterns. The SEM images clearly displays that the films have even surface without any voids and crack. The EDX spectra confirm that Zn, O, and Ga elements were present in films. The UV-visible spectra show that the optical absorption of the films in UV region is similar to 5 % and the optical band gap energy was from 3.20 to 3.30 eV. The Hall effect measurements result clear that all the films have n-type conductivity with minimum resistivity (3.95 x 10(- 3)Omega-cm) and maximum carrier concentration (7.23 x 10(20)cm(- 3)) for 6 % of gallium doped film. The photo-sensing parameters such as external quantum efficiency (EQE), and detectivity (D) has a maximum value for 6 % of gallium doped film. The 6 % of gallium doped film exhibit a better photocurrent (149.1 x 10(- 7) A) than other films.