Density functional theory predictions for blue luminescence and nonlinear optical properties of carbon-doped gallium nitride

The TD-B3LYP method and the plane-wave formalism of DFT method were applied to predict the blue luminescence and nonlinear optical effect of C-doped GaN, respectively. The introduction of carbon dopant will generate different acceptor or donor levels, which are mainly composed by p electronic state, within the energy gap of GaN. Exploring the calculated luminescence spectra based on the optimized excited-state structure, CN:GaN exhibits high luminescence intensity and has nice monochromatic property. In addition, the corresponding second-order nonlinear optical coefficients are considerable, χ(2)xzx=−15.07 pm/V and χ(2)zzz=26.91 pm/V, which are about 28 times and 50 times of the second-order optical coefficient of KDP crystal.