Ternary Alloy Epitaxial Layers (ternary + alloy_epitaxial_layer)

Distribution by Scientific Domains


Selected Abstracts


Localized biexcitons in AlxGa1,xN ternary alloy epitaxial layers

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 2 2003
Y. Yamada
Abstract Excitonic optical properties of AlxGa1,xN ternary alloy epitaxial layers have been studied by means of photoluminescence (PL), time-resolved PL, and PL excitation (PLE) spectroscopy. The luminescence line due to radiative recombination of biexcitons was clearly observed in an Al0.08Ga0.92N epitaxial layer. The PL decay time of excitons and biexcitons was estimated to be 350 and 210 ps, respectively. PLE spectroscopy of biexcitons enabled us to observe a two-photon absorption process of biexcitons. On the basis of the energy separation between exciton resonance and two-photon biexciton resonance, the binding energy of biexcitons in Al0.08Ga0.92N was estimated to be 15 ± 2 meV. This value was approximately 2.5 times as large as the binding energy of biexcitons in GaN. This value was also found to be comparable to the observed energy separation between the exciton luminescence and the biexciton luminescence, which indicated the strong localization of biexcitons. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Exciton localization in Al-rich AlGaN ternary alloy epitaxial layers

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7-8 2010
Hideaki Murotani
Abstract Exciton localization in Al-rich AlGaN ternary alloy epitaxial layers has been studied by means of temperature-dependent photoluminescence (PL) spectroscopy. Anomalous temperature dependence of the PL peak energy (red-blue shift) was observed, which enabled us to estimate the localization energy of excitons. The localization energy increased as the 1.2th power of the exciton linewidth. The value of exponent for Al-rich alloys was smaller than that for Ga-rich alloys. This indicated that the excitons in Al-rich alloys were strongly localized compared to that in Ga-rich alloys. In addition, the exponent value for Al-rich alloys increased with increasing excitation power density. This increase in the exponent suggested that the exciton population approached the extended states owing to the saturation of localized states by photo-generated excess excitons. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]