Gallium nitride nanowire devices and photoelectric properties

• The photoelectric properties of CVD-grown multi-prong GaN nanowires were studied.
• UV lights with various wavelengths (254 and 365 nm) and power levels were used.
• GaN NWs show high positive photoelectric response via molecular sensitization model.
• Multi-prong GaN nanowires exhibit moderate persistent photocurrent during decay.
• The persistent photocurrent is due to a reduced surface recombination process.

This paper presents an investigation of photoelectric properties of the CVD-grown multi-prong GaN nanowires. The multi-prong growth mechanism produces uniform high density long GaN nanowires, which is very significant for scale-up manufacturing opportunities. Photoelectric studies of the GaN nanowires have been conducted at various light sources with wavelengths of 254 nm and 365 nm. The 254 nm-light exposure resulted in a larger photocurrent increase compared to that of 365 nm-light exposure, which is attributed to the larger number of the photogenerated carriers owing to the higher photon energy. The positive photoelectric response of the GaN nanowires is attributed to the molecular sensitization mechanism. Furthermore, the GaN nanowires devices exhibited moderate persistent photocurrent. These findings suggest a reduced surface recombination process due to the depletion surface charge layer. In summary, the multi-prong GaN nanowires could be utilized as photoconductors, photodetectors, and various photosensing elements in many highly integrated optoelectronic devices.