Structural and optoelectronic characteristics of well-aligned ZnO nanorod arrays for photodiodes

Structural and optoelectronic characteristics of the well-aligned ZnO nanorod arrays were achieved by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, photoluminescence (PL) and micro-Raman spectroscopy. The results indicated that the well-aligned ZnO nanorod with wurtzite structure was preferred oriented in the [002] c-axis direction. ZnO nanorod-based Schottky-barrier photodiodes has been also fabricated and characterized. With an incident wavelength of 370 nm and 5 V applied bias, it was found that maximum photoresponsivity of the photodiode was 0.051 A/W, which corresponded to a quantum efficiency of 21%.