Photoresponse properties of p-type ZnSe nanowire photodetectors

Nanophotodetectors are constructed based on individual p-type ZnSe nanowires (NWs), and the photoresponse properties are investigated. The nanophotodetectors show high sensitivity and fast response speed to the incident light with a sharp cutoff at 470 nm. The light-to-dark currents ratio I_light/I_dark is approximately two orders of magnitude; photoconduction is 20.5 nS at incident light intensity of 5.11 mWcm^-2. The response characteristics reveal that different energy levels (shallow and deep) in the bandgap and defects on the NW surface play an important role in the recombination. The ZnSe NW photodetector with good reliability and reproducibility will have great potential application in optoelectronic nanodevices.