کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1547716 997642 2006 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Photoluminescence studies of confined states in AlGaAs/GaAs asymmetric quantum well
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد مواد الکترونیکی، نوری و مغناطیسی
پیش نمایش صفحه اول مقاله
Photoluminescence studies of confined states in AlGaAs/GaAs asymmetric quantum well
چکیده انگلیسی

In the recombination spectra of AlGaAs/GaAs heterostructures, a peculiar and asymmetric photoluminescence (PL) band F has previously been reported [Aloulou et al., Mater. Sci. Eng. B 96 (2002) 14] to be due to recombinations of confined electrons from the two-dimensional electron gas (2DEG) formed at AlGaAs/GaAs interface in asymmetric quantum well (AQW). Detailed experiments are reported here on GaAs/Al0.31Ga0.69As/GaAs:δSi/Al0.31Ga0.69As/GaAs samples with different spacer layer thicknesses. We show that the band F is the superposition of two PL bands F′ and F″ associated, respectively, to AQW and a symmetric quantum well (SQW). In the low excitation regime, the F′ band present a blue shift (4.4 meV) followed by important red shift (16.5 meV) when increasing optical excitation intensity. The blue shift in energy is interpreted in terms of optical control of the 2DEG density in the AQW while the red shift is due to the narrowing of the band gaps caused by the local heating of the sample and band bending modification for relatively high-optical excitation intensity. Calculation performed using self-consistent resolution of the coupled Schrödinger–Poisson equations are included to support the interpretation of the experimental data.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica E: Low-dimensional Systems and Nanostructures - Volume 33, Issue 2, July 2006, Pages 325–330
نویسندگان
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