Investigation of Optical Nonlinearities, and Carrier Dynamics, in In-Rich InGaN Alloys

S. Nargelas a, T. Malinauskas a, K. Jarasiunas a, E. Dimakis b and A. Georgakilas b a Department of Semiconductor Optoelectronics, Institute of Materials Science and Applied Research, Vilnius University, Sauletekio Av. 9-3, LT-10222 Vilnius, Lithuania b Microelectronics Research Group, Physics Department, University of Crete, P.O. Box 2208, 71003 Heraklion, Greece, and IESL, FORTH, P.O. Box 1527, 71110 Heraklion, Greece

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Received: 26 08 2007;

We present experimental studies of nonequilibrium carrier dynamics in InGaN alloys with 70-90% content of In by using picosecond transient grating technique. The observed faster recombination rate in alloys with higher Ga content and formation of a thermal grating via a lattice heating, being more pronounced for layers with larger band gap, indicated that the main reason of the heating is not the excess energy of photons, but the defect density which increases with Ga content. A gradual decrease in carrier lifetime with excitation or with increasing temperature in 50-300 K range point out the role of potential barriers in carrier recombination.

DOI: 10.12693/APhysPolA.113.839 PACS numbers: 78.47.J-, 72.20.Jv