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Intersubband Transitions (intersubband + transition)
Selected AbstractsOptical properties of InAs/InP quantum dot stack grown by metalorganic chemical vapor depositionPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 4 2003Heedon Hwang Abstract The 5-layer InAs quantum dot (QD) stack was grown on an (001) InP substrate by low pressure-metalorganic chemical vapor deposition. 40 nm InP spacer layers were inserted between the InAs QDs. The integrated intensity of the photoluminescence peak at 300 K was over 12% of that at 10 K. Far-infrared absorption peaks were observed at 819 cm,1 (101.64 meV) and 518 cm,1 (64.08 meV) from this structure at room temperature by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Raman analysis showed that the peak at 819 cm,1 was attributed to a plasmon related peak in the n-type InP substrate. The absorption peak at 518 cm,1 was regarded as a peak related with intersubband transition in the InAs QDs, suggesting that room temperature operating quantum dot devices may be fabricated. [source] Use of contactless electroreflectance in the development of quantum cascade lasers from ZnCdSe/ZnCdMgSePHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 5 2009Martin Muñoz Abstract Electro-modulation techniques have been used extensively to analyze interband transitions in materials and devices, however little has been done to use these techniques for the analysis of intersubband transitions in materials and devices. In this work, contactless electroreflectance has been used to determine the conduction band offset of ZnCdSe/ZnCdMgSe quantum well structures. Toward the development of quantum cascade lasers, multi-quantum well structures with intersubband absorption at 178 meV were analyzed using contactless electro-reflectance. Finally, quantum cascade laser structures were designed for emission at 4.8 ,m. The multi-quantum well structures presented an excellent agreement between the designed and measured absorption and emission, respectively. This work demonstrates that contactless electro-reflectance can accurately determine the conduction band offset and is useful in the analysis of intersubband transitions. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Polaron signatures in the line shape of semiconductor ;intersubband transitions: quantum kinetics of the electron,phonon interactionPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 11 2004S. Butscher Abstract We present a theory of the optical line shape of coherent intersubband transitions in a semiconductor quantum well, considering non-Markovian LO-phonon scattering as major broadening mechanism. We show that a quantum kinetic approach leads to additional polaron resonances and a resonance enhancement for gap energies close to the phonon energy. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] |