Recombination dynamics in InGaN/GaN quantum wells: role of the piezoelectric field versus carrier localization

We present an experimental investigation of InxGa1−xN/GaN multiple quantum well structures, with well widths ranging between 10 and 40 A and an indium content 0.03 < x < 0.07. Given such values, both the electric built-in field and localization due to potential fluctuation affect the carrier dynamics. We will show that, by means of time-integrated, time-resolved photoluminescence spectra and cathodoluminescence experiments, different processes affecting the recombination dynamics can be evidenced. A comparison with theoretical simulations of the carrier dynamics provides a nice agreement with experiments. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)