Doping behavior of In_0.1Ga_0.9N codoped with Si and Zn

We have studied the codoping characteristics of In_0.1Ga_0.9N : ZnSi/GaN grown on sapphire (0 0 0 1) substrates. The films were grown in a horizontal MOVPE reactor at the reduced pressure of 300 Torr and 820°C. The FWHMs of the DCXRD for (0 0 0 2) diffraction and PL for band edge emission at room temperature from the undoped In_0.1Ga_0.9N are 11 arcmin and 80 meV. With the appropriate Zn only doping in undoped In_0.1Ga_0.9N, the emission peak is shifted from 410 nm which originates from the band edge emission to blue of 460 nm which resulted from the band to acceptor transition due to a deep acceptor level. Besides the shift of the emission peak, the yellow luminescence peak around 600 nm nearly disappeared by the Zn doping. With the optimum codoping of Si in In_0.9Ga_0.9N : Zn, the intensity of blue emission increases abruptly by decreasing the defect density playing an important role as a nonradiative center.