Rapid Fabrication of ZnO Tetrapod Based Photoconductive Cell by Microwave Synthesis Technology

Abstract

ZnO tetrapods were synthesized in a few seconds by "environmentally green" microwave evaporation of Zn powder in air atmosphere. No any kind of organic solvents or precursors were used. X-ray diffractometry (XRD) indicated that synthesized tetrapods have well developed hexagonal wurtzite structure. Photoconductive cell performed high sensitivity to ultraviolet light (UV) in the range of 300 to 400 nm wavelength. Notably device is totally blind to visible light. Maximum spectral response was observed at 370 nm wavelength. UV-visible spectrophotometer revealed absorbance at UV region with cut-off wavelength at 370 nm which corresponds to 3.4 eV energy bandgap. Response recovery time of photoconductive cell was 50 seconds at room temperature. Resistivity changed from 70 M Omega in dark to less than 1.4 M Omega at 18 mW/cm(2) 370 nm wavelength light irradiation. Results were discussed.