Ultraviolet Photoconductive Hydrogenated Amorphous and Microcrystalline GaN

Hydrogenated amorphous and microcrystalline GaN films are grown by remote-plasma metalorganic chemical vapor deposition at a substrate temperature below 300°C. These films have a stoichiometric composition with 17 to 30 at% hydrogen. The films on aluminum exhibit a fast ultraviolet (UV) photoresponse with a photocurrent to dark current ratio of 104. The normalized photoconductivity, ηµτ of the film with E opt of 3.2 eV is of the order of 10-6 cm2·V-1. Photodegradation effects have never been observed even after 5 h of irradiation with intense UV light of 500 mW/cm2.