Nonradiative recombination due to Ar implantation induced point defects in GaInN/GaN quantum wells

We quantitatively investigate nonradiative recombination at point defects via temperature dependent time-resolved photoluminescence spectroscopy on argon implanted MOVPE-grown GaInN/GaN single quantum wells (QW). An implantation dose dependent (doses: 1011 cm-2-1013 cm-2) reduction of nonradiative lifetimes from several nanoseconds (unimplanted sample) to less than 100 ps at room temperature is observed. This shortening of nonradiative lifetimes is attributed to nonradiative recombination due to increased implantation induced defect densities. An effective hole capture coefficient can be estimated to about 109 cm3s-1 via the measured nonradiative lifetimes and simulated (SRIM) defect densities. The thermal stability of the defects is analyzed using rapid thermal annealing at 800 circle C in order to recover the crystal from implantation damage. At high temperatures, nonradiative recombination in the barriers becomes dominant: defect density dependent losses with an activation energy equal to half the difference between the GaN band gap and the peak position of the QW luminescence are observed.