Electronic properties of arsenic-doped gallium nitride

Abstract

Arsenic-doped GaN films were grown via metalorganic chemical vapor deposition using trimethylgallium, ammonia, and arsine precursors. The arsenic concentration increases from 3×1016 to 5×1017 cm−3 in response to a change in arsine mole fraction from 3.3×102 to 3.2×104 ppm. The electron mobility increases with arsenic content reaching a maximum value of 374 cm2/V s at 300 K. In addition, the integrated photoluminescence intensity exhibits a 35-fold increase in magnitude at 300 K. To explain these findings, a simple physical model is proposed in which arsenic “impurities” occupy otherwise vacant sites on both the gallium and nitrogen sublattices.