First-principle calculation for luminescent-effects of Si and Zn impurities in GaN

Phosphor-free GaN-based white-light LED which is usually generated as a combination of the blue bandedge emission and a yellow-green broad-band emission has been approved to be more reliable than phosphor-based white-light LED. First-principle method was employed to investigate the luminescent-effects of Si and Zn impurities in phosphor-free GaN-based LED. By explicitly calculating the formation energies and defect levels, the origin of yellow-green broad-band emission in Si and Zn co-dopoed InGaN/GaN multiquantum wells(MQWs) were discussed and determined. We propose that the electron transition between Zn_i/Zn_N-Si_N D-A pairs are responsible for the observed yellow-green broad-band emission.