Carrier diffusion and recombination in highly excited InGaN/GaN heterostructures

✍ Scribed by 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.

• Book ID: 105363192
• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 489 KB
• Volume: 202
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200461351

✦ Synopsis

Abstract

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)