Photoconductive Gain and Noise Properties of ZnO Nanorods Schottky Barrier Photodiodes

In this investigation, ZnO nanorods Schottky barrier photodiodes were fabricated for UV detection. The Schottky barrier photodiodes had a rectifying current flow. Under 370 nm illumination, it was found that the ZnO nanorods Schottky barrier photodiodes showed high responsivity of 104.14 A/W at -1 V. The high responsivity can be attributed to large surface-to-volume ratio and oxygen adsorption and desorption at the ZnO surfaces. It was also found that the photocurrent linear increased with incident power density increased. The photocurrents have no obvious saturation at large bias, indicating the sample is very ideal for practice use. Further, under a -1 V applied bias, noise equivalent power and normalized detectivity (D*) were 8.01 × 10^-13 Wand 2.77 × 10¹¹ cm Hz^0.5 W^-1, respectively.