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HL: Fachverband Halbleiterphysik

HL 51: Focus Session: Role of polarization fields in nitride devices II

HL 51.4: Vortrag

Mittwoch, 18. März 2015, 16:00–16:15, ER 164

Nonradiative recombination mechanisms in non- and semipolar GaInN/GaN quantum wells — •Manuela Klisch, Torsten Langer, Holger Jönen, Fedor Alexej Ketzer, Heiko Bremers, Uwe Rossow, and Andreas Hangleiter — Institut für Angewandte Physik, TU Braunschweig

Via temperature-dependent time-resolved photoluminescence spectroscopy, we investigate the nonradiative recombination of excess charge carriers in non- and semipolar quantum well structures of varying indium composition grown via metalorganic vapor phase epitaxy on low defect density GaN. We demonstrate that for InN mole fractions of about 30% within the quantum well, the nonradiative carrier lifetimes in m-plane quantum wells match the corresponding values for polar quantum wells of about 100 ps. The shortening of nonradiative lifetimes with increasing indium content is weak compared to polar quantum wells indicating that the mechanisms of defect generation differ among different growth planes. Possibly, this is related to different influences of slip planes on the plastic relaxation of the compressively strained quantum wells. However, comparable nonradiative lifetimes for (1122)-, (2021)-, m- and a-plane quantum wells have been observed. Due to the small piezoelectric field component perpendicular to the quantum well plane, which reduces the radiative recombination probability in polar quantum wells, this observation is very promising to outperform the internal quantum efficiency of polar quantum wells towards green emission using non- or semipolar quantum wells.