The effects of point defects upon In-rich InAlN were studied by using 2MeV He+ bombardment to vary the defect concentration. The localized native defects in In1− xAlxN( x < 0.45) were predominantly donors; with energy levels located above the conduction-band edge. The electron concentration increased, and the optical absorption-edge blue-shifted, with increasing bombardment fluence before saturating at high fluences. Saturation occurred when the Fermi level reached the Fermi level stabilization energy, which was the average energy of localized native defects, at 4.9eV below the vacuum level. The energy position of the native defects explained the initial increase, followed by quenching, of the photoluminescence intensity as well as the blue-shift of the photoluminescence peak with increasing irradiation fluence.

Properties of Native Point Defects in In1−xAlxN Alloys. R.E.Jones, S.X.Li, K.M.Yu, J.W.Ager, E.E.Haller, W.Walukiewicz, H.Lu, W.J.Schaff: Journal of Physics D, 2009, 42[9], 095406