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Carrier diffusion and recombination in highly excited InGaN/GaN heterostructures
Author(s) -
Jarašiūnas K.,
Aleksiejūnas R.,
Malinauskas T.,
Sūdžius M.,
Miasojedovas S.,
Juršėnas S.,
Žukauskas A.,
Gaska R.,
Zhang J.,
Shur M. S.,
Yang J. W.,
Kuokštis E.,
Khan M. A.
Publication year - 2005
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200461351
Subject(s) - heterojunction , photoluminescence , saturation (graph theory) , materials science , excited state , metalorganic vapour phase epitaxy , optoelectronics , excitation , indium , spontaneous emission , four wave mixing , sapphire , quantum well , atomic physics , optics , epitaxy , laser , layer (electronics) , physics , nonlinear optics , nanotechnology , mathematics , combinatorics , quantum mechanics
Time‐resolved four‐wave mixing and photoluminescence techniques have been combined for studies of MOCVD‐grown In x Ga 1– x N/GaN/sapphire heterostructures with different indium content (0.08 < x < 0.15). In‐plane diffusion and recombination of spatially‐modulated carriers, confined in the front layer of 50‐nm‐thick InGaN, were monitored by a probe beam diffraction and provided an average value of a bipolar diffusion coefficient D ≈ 1–1.5 cm 2 /s and its dependence on the In content. A complete saturation of four‐wave mixing (FWM) efficiency vs excitation energy was found prominent in a layer with 10% of In. The latter effect of saturation correlated well with the dependence of quantum efficiency of stimulated emission on In content in heterostructures. Short decay times of stimulated emission (∼10 ps) measured by time‐resolved PL in highly excited structure allowed us to attribute the FWM saturation effect to the threshold of stimulated recombination. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)