Simultaneous growth of a GaN p/n lateral polarity junction by polar selective doping

Differences in surface energy between the Ga-polar orientation and the N-polar orientation of GaN translate into a completely different behavior for the incorporation of intentional and unintentional impurities. Oxygen is found to be an impurity with higher concentrations in N-polar films than in Ga-polar films and is the cause for the high n-type carrier concentration observed in N-polar films. We fabricated a lateral p/n junction in GaN by the simultaneous growth of p- and n-type regions, utilizing the doping selectivity of the two different polar domains. The N-polar domains were n type with a carrier concentration of 1.7x10(19) cm(-3), predominantly due to high oxygen incorporation, while Ga-polar domains were p type with a carrier concentration of 1.7x10(17) cm(-3). No significant difference in Mg incorporation was observed between the two polar domains. This junction showed the characteristics that define a p/n junction: current rectification, electroluminescence, and the photovoltaic effect. (C) 2007 American Institute of Physics.