Modulation of Band Gaps of Codoping GaN: A First Principles Study

Abstract

To improve the solar energy conversion of GaN for photocatalytic, the band gap of GaN should be tailored to match with visible light absorption, we calculated that Cr/C codoping effectively narrows the band gap of GaN by using first-principles calculations. Cr/C codoping can split the band gap with the formation of an intermediate band. Positive defect pair binding energy indicates that the defect pairs are stable with respect to the isolate impurity in the sample. The band gap narrowing can be optimized to shift light absorption into the peak of the visible spectral region , which enable maximal utilization of sunlight and thus offer immense potential for applications in solar energy conversion.