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Title: High pressure and time resolved studies of optical properties of n-type doped GaN/AlN multi-quantum wells: Experimental and theoretical analysis

Abstract

High-pressure and time-resolved studies of the optical emission from n-type doped GaN/AlN multi-quantum-wells (MQWs) with various well thicknesses are analysed in comparison with ab initio calculations of the electronic (band structure, density of states) and optical (emission energies and their pressure derivatives, oscillator strength) properties. The optical properties of GaN/AlN MQWs are strongly affected by quantum confinement and polarization-induced electric fields. Thus, the photoluminescence (PL) peak energy decreases by over 1 eV with quantum well (QW) thicknesses increasing from 1 to 6 nm. Furthermore, the respective PL decay times increased from about 1 ns up to 10 μs, due to the strong built-in electric field. It was also shown that the band gap pressure coefficients are significantly reduced in MQWs as compared to bulk AlN and GaN crystals. Such coefficients are strongly dependent on the geometric factors such as the thickness of the wells and barriers. The transition energies, their oscillator strength, and pressure dependence are modeled for tetragonally strained structures of the same geometry using a full tensorial representation of the strain in the MQWs under external pressure. These MQWs were simulated directly using density functional theory calculations, taking into account two different systems: the semi-insulating QWs and the n-doped QWs with themore » same charge density as in the experimental samples. Such an approach allowed an assessment of the impact of n-type doping on optical properties of GaN/AlN MQWs. We find a good agreement between these two approaches and between theory and experimental results. We can therefore confirm that the nonlinear effects induced by the tetragonal strain related to the lattice mismatch between the substrates and the polar MQWs are responsible for the drastic decrease of the pressure coefficients observed experimentally.« less

Authors:
 [1];  [2]; ;  [1]; ; ; ;  [3];  [4]; ;  [5];  [6];  [1];  [2]
  1. Institute of Physics Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02-668 Warsaw (Poland)
  2. (Poland)
  3. Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw (Poland)
  4. University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw (Poland)
  5. Université Grenoble-Alpes, 38000 Grenoble (France)
  6. (France)
Publication Date:
OSTI Identifier:
22598822
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 120; Journal Issue: 9; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM NITRIDES; COMPARATIVE EVALUATIONS; CRYSTAL DEFECTS; CRYSTALS; DENSITY FUNCTIONAL METHOD; DENSITY OF STATES; DOPED MATERIALS; ELECTRIC FIELDS; GALLIUM NITRIDES; NONLINEAR PROBLEMS; N-TYPE CONDUCTORS; OPTICAL PROPERTIES; OSCILLATORS; PHOTOLUMINESCENCE; PRESSURE COEFFICIENT; PRESSURE DEPENDENCE; QUANTUM WELLS; THICKNESS; TIME RESOLUTION

Citation Formats

Kaminska, A., Cardinal Stefan Wyszynski University, College of Science, Department of Mathematics and Natural Sciences, Dewajtis 5, 01-815 Warsaw, Jankowski, D., Sobczak, K., Strak, P., Sakowski, K., Grzanka, E., Krukowski, S., Korona, K. P., Beeler, M., Monroy, E., CEA Grenoble, INAC-PHELIQS, 17 av. des Martyrs, 38000 Grenoble, Borysiuk, J., and University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw. High pressure and time resolved studies of optical properties of n-type doped GaN/AlN multi-quantum wells: Experimental and theoretical analysis. United States: N. p., 2016. Web. doi:10.1063/1.4962282.
Kaminska, A., Cardinal Stefan Wyszynski University, College of Science, Department of Mathematics and Natural Sciences, Dewajtis 5, 01-815 Warsaw, Jankowski, D., Sobczak, K., Strak, P., Sakowski, K., Grzanka, E., Krukowski, S., Korona, K. P., Beeler, M., Monroy, E., CEA Grenoble, INAC-PHELIQS, 17 av. des Martyrs, 38000 Grenoble, Borysiuk, J., & University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw. High pressure and time resolved studies of optical properties of n-type doped GaN/AlN multi-quantum wells: Experimental and theoretical analysis. United States. doi:10.1063/1.4962282.
Kaminska, A., Cardinal Stefan Wyszynski University, College of Science, Department of Mathematics and Natural Sciences, Dewajtis 5, 01-815 Warsaw, Jankowski, D., Sobczak, K., Strak, P., Sakowski, K., Grzanka, E., Krukowski, S., Korona, K. P., Beeler, M., Monroy, E., CEA Grenoble, INAC-PHELIQS, 17 av. des Martyrs, 38000 Grenoble, Borysiuk, J., and University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw. Wed . "High pressure and time resolved studies of optical properties of n-type doped GaN/AlN multi-quantum wells: Experimental and theoretical analysis". United States. doi:10.1063/1.4962282.
@article{osti_22598822,
title = {High pressure and time resolved studies of optical properties of n-type doped GaN/AlN multi-quantum wells: Experimental and theoretical analysis},
author = {Kaminska, A. and Cardinal Stefan Wyszynski University, College of Science, Department of Mathematics and Natural Sciences, Dewajtis 5, 01-815 Warsaw and Jankowski, D. and Sobczak, K. and Strak, P. and Sakowski, K. and Grzanka, E. and Krukowski, S. and Korona, K. P. and Beeler, M. and Monroy, E. and CEA Grenoble, INAC-PHELIQS, 17 av. des Martyrs, 38000 Grenoble and Borysiuk, J. and University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw},
abstractNote = {High-pressure and time-resolved studies of the optical emission from n-type doped GaN/AlN multi-quantum-wells (MQWs) with various well thicknesses are analysed in comparison with ab initio calculations of the electronic (band structure, density of states) and optical (emission energies and their pressure derivatives, oscillator strength) properties. The optical properties of GaN/AlN MQWs are strongly affected by quantum confinement and polarization-induced electric fields. Thus, the photoluminescence (PL) peak energy decreases by over 1 eV with quantum well (QW) thicknesses increasing from 1 to 6 nm. Furthermore, the respective PL decay times increased from about 1 ns up to 10 μs, due to the strong built-in electric field. It was also shown that the band gap pressure coefficients are significantly reduced in MQWs as compared to bulk AlN and GaN crystals. Such coefficients are strongly dependent on the geometric factors such as the thickness of the wells and barriers. The transition energies, their oscillator strength, and pressure dependence are modeled for tetragonally strained structures of the same geometry using a full tensorial representation of the strain in the MQWs under external pressure. These MQWs were simulated directly using density functional theory calculations, taking into account two different systems: the semi-insulating QWs and the n-doped QWs with the same charge density as in the experimental samples. Such an approach allowed an assessment of the impact of n-type doping on optical properties of GaN/AlN MQWs. We find a good agreement between these two approaches and between theory and experimental results. We can therefore confirm that the nonlinear effects induced by the tetragonal strain related to the lattice mismatch between the substrates and the polar MQWs are responsible for the drastic decrease of the pressure coefficients observed experimentally.},
doi = {10.1063/1.4962282},
journal = {Journal of Applied Physics},
number = 9,
volume = 120,
place = {United States},
year = {Wed Sep 07 00:00:00 EDT 2016},
month = {Wed Sep 07 00:00:00 EDT 2016}
}