Photoexcited carrier recombination in wide m-plane InGaN/GaN quantum wells

Carrier recombination in single 10 nm wide m-plane homoepitaxial In0.15Ga0.85N/GaN quantum wells was examined by time-resolved photoluminescence. The radiative recombination time at 3.5 K was found to be short, about 0.5 ns. This value and the single-exponential luminescence decay show that the localized exciton recombination is not affected by the in-plane electric field. At room temperature, the nonradiative recombination was prevalent. The data indicate that the nonradiative recombination proceeds via efficient recombination centers. Complexes of Ga vacancies with oxygen and/or related interface defects are suggested to play this role and thus provide a direction for future improvements in materials' quality.