Electrical behavior of Mg doped cubic GaN on c-GaN structure

Magnesium doped cubic GaN films were epitaxially grown using a metalorganic chemical vapor deposition system. In an exploratory fashion, growth conditions were varied to obtain quasi mono-crystalline surfaces and by this mean remove the hexagonal fraction present in the samples. Hall effect measurements indicate a carrier concentration in Mg doped c-GaN films between 5×1017 and 8×1018 cm−3 with p-type carriers. Electrical studies were carried out in a homojunction formed by c-GaN films with different conductivity; our findings demonstrate the GaN homojunction has a rectifier effect, and presents a repeatable negative differential resistance attributed to the transferred electron effect in deep levels. We confirmed that the Mg doped c-GaN films are suitable for optoelectronic device manufacturing.