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

Abstract 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 × 10 3 . The detection parameters revealed 0.49 mA W −1 responsivity and 2.69 × 10 9 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.