Ultraviolet Photodetector Fabricated From Multiwalled Carbon Nanotubes/Zinc-Oxide Nanowires/p-GaN Composite Structure

An ultraviolet (UV) heterojunction photodetector was fabricated from multiwalled carbon nanotubes (MWCNTs)/zinc-oxide nanowires (NWs)/p-GaN composite structure. The photodetector demonstrated significant rectifying characteristics and relative fast transient response with response time on the order of milliseconds. Under back illumination, the photodetector exhibited a narrow bandpass photoresponse spectrum (13-nm full-width at half-maximum) centered at 375 nm with a maximum responsivity of 6 mA/W. The good performance of this heterojunction photodetector is attributed to improved carrier transport and collection efficiency through the MWCNTs network deposited on top of the ZnO NWs.