Photoconductivity of catalyst-free grown aluminum nitride nanowires

This paper presents photoconductivity investigation of catalyst-free AlN nanowire synthesized by chemical vapor deposition using Al and NH3, as source materials. The growth runs have been carried out at 1100°C under H2 as carrier gas. The growth runs have resulted in very high quality and dense AlN nanostructures. In addition, nanowire FET devices have been fabricated. A unique annealing scheme has been implemented to improve contacts between nanowires and electrodes, which resulted in very consistent electrical measurements. Photoconductivity studies of the AlN nanowires have been conducted at various light sources with wavelengths of 254 nm, 365 nm, 532 nm and 633 nm using a semiconductor parameter analyzer. Significant positive photocurrent responses have been measured under different photon energy excitations. Furthermore, photocurrent decay has been very rapid after the illumination ended. These studies will provide crucial information and insights for the development of UV optoelectronic devices and light sensors. The grown nanowires and devices have been characterized by SEM, EDS, XRD, and semiconductor parameter analyzer.