Sixfold symmetry of excitonic transition energies in c-plane for wurtzite GaN

The optical properties of the strained wurtzite GaN are investigated theoretically within the nearest neighbor tight-binding method. The piezoelectric effect is also taken into account. The empirical rule has been used in the strained band-structure calculation. The results show that the excitonic transition energies are anisotropic in the c-plane in a high electronic concentration system and have a 60 degrees periodicity, which is in agreement with experiment. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3001937]

973 Program 2006CB604908 2006CB921607 National Natural Science Foundation of China 60625402 This work was supported by the 973 Program (Grant Nos. 2006CB604908 and 2006CB921607) and the National Natural Science Foundation of China (Grant No. 60625402).