Photodiode behavior and capacitive performance of ZnO nanoflakes synthesized by electrochemical deposition

ZnO flake interlayers were fabricated by the electrochemical deposition technique on p-Si to obtain Au/ZnO/p-Si heterostructures for Schottky-type photodiode applications and to test the capacitive performance of the structures. ZnO flake structures were investigated by x-ray diffractometry and scanning electron microscopy measurements, and their crystalline and flake-like structures were confirmed. The Au/ZnO/p-Si heterostructures were characterized by current-voltage (I-V) measurements for various illumination densities of light from dark to 150 mW cm-2. Various heterostructure parameters such as the ideality factor, barrier height, series resistance and rectifying ratio (RR) values were determined by I-V characteristics. The heterostructure exhibited a high RR of 6.85 x 103. The detection parameters revealed 0.49 mA W-1 responsivity and 2.69 x 109 Jones specific detectivity values. Furthermore, capacitance-voltage (C-V) measurements were employed to obtain the capacitive behavior of the Au/ZnO/p-Si heterostructure at various frequencies. Based on these results, Au/ZnO/p-Si heterostructures have potential for photodiode applications.