Resistivity reduction of low temperature grown p-Al0.09Ga0.91N by suppressing the incorporation of carbon impurity

Reducing the resistivity of low temperature grown p-Al0.09Ga0.91N layers is crucial to improving the performance of GaN-based laser diodes. In this study, growth conditions of low temperature grown p-Al0.09Ga0.91N layers are monitored and the role of C impurity is investigated systematically. On the basis of the dependence of resistivity on C concentration and the photoluminescence analysis, it is found that C impurities act as donors in p-Al0.09Ga0.91N layer, and reducing the C concentration can reduce its compensation effect on Mg acceptor. Finally, a low resistivity of 4.2 Ω·cm is achieved for the low temperature grown p-Al0.09Ga0.91N