First principle study of Mg, Si and Mn co-doped GaN

Calculations of electronic structures and optical properties of Mg (or Si) and Mn co-doped GaN were carried out by means of first-principle plane-wave pesudopotential (PWP) based on density functional theory - The spin polarized impurity bands of deep energy levels were found for both systems. They are half metallic and suitable for spin injectors. Compared with GaN Mn, GaN Mn-Mg exhibits a significant increase in T-C 1 while the 1.3 eV absorption peak in GaN Mn disappears due to addition of Mg. In addition, a strong absorption peak due to T-4(1) (F) -> T-4(2) (F) transition of Mn4+ were observed near 1.1 eV. Nevertheless, GaN Mn-Si failed to show increase of T-C, and the absorption peak was not observed at the low energy side.

National Natural Science Foundation of China 50602018 Natural Science Foundation of Guangdong Province, Chin 06025083 Research Project of Science and Technology of Guangdong Province, China 2006A10802001 Key Research Project of Science and Technology of Guangzhou, Guangdong Province, China 2005Z12D0071 Crucial Field and Key Breakthrough Project of Guangdong Province and Hongkong, China 207A010501008 Project supported by the National Natural Science Foundation of China (Grant No. 50602018), the Natural Science Foundation of Guangdong Province, China (Grant No. 06025083), the Research Project of Science and Technology of Guangdong Province, China( Grant No. 2006A10802001), the Key Research Project of Science and Technology of Guangzhou, Guangdong Province, China ( Grant No. 2005Z12D0071) the Crucial Field and Key Breakthrough Project of Guangdong Province and Hongkong, China (207A010501008).