Data associated with 'Impact of alloy fluctuations and Coulomb effects on the electronic and optical properties of c-plane GaN/AlGaN quantum wells: Insights from theory and experiment'

Published: 29-11-2019| Version 1 | DOI: 10.17632/y932x24tpy.1
Contributors:
Abas Roble,
Saroj Patra,
Fabien Massabuau,
Martin Frentrup,
Philip Dawson,
Marina Leontiadou,
Menno Kappers,
Rachel Oliver,
Darren Graham,
Stefan Schulz

Description

This is the data for Figure 1, 3-8 of the research paper titled 'Impact of alloy fluctuations and Coulomb effects on the electronic and optical properties of c-plane GaN/AlGaN quantum wells: Insights from theory and experiment'. The data in each file are numeric data organised in 2 columns (column 1 contains the abscissa, and column 2 the ordinate), saved as .dat files. The 7 figures are: Figure 1. XRD ω-2θ-scans of the 0002 reflection showing the satellite peaks of the GaN/AlGaN MQW structures of Sample A (top) and Sample B (bottom). Figure 3. Normalized PL spectra and 1/e decay times obtained at a temperature T = 10 K for GaN/AlGaN MQWs with well widths L = . 2 4 w nm (Sample A, right) and L = . 6 8 w nm (Sample B, left). The solid curves correspond to PL spectra obtained with a photo-excitation energy of 4.66 eV (λ = 266 nm). The circles represent the 1/e decay times measured across the displayed PL spectra. Figure 4. Peak PL energy as a function of temperature T for GaN/AlGaN MQWs with well widths Lw of L = . 2 4 w nm (Sample A) and L = . 6 8 w nm (Sample B). The filled circles show the raw data, and the triangles show the data with the band gap temperature dependence removed using the two-parameter Varshni expression. The inset shows the PL peak energy data for Sample A, for T ≤ 160 K. Figure 5. PL time decay curves measured at the PL peak energy of the T = 10 K spectra for GaN/AlGaN MQWs with well widths Lw of 2.4 nm (Sample A) and 6.8 nm (Sample B) together with the system response of the PL decay time measuring setup. Figure 6. Isosurface plots of the electron (red) and hole (blue) ground state charge densities in the absence (left column, (a,b)) and in the presence of (right column, (c,d)) Coulomb (excitonic) effects. The results are displayed for an arbitrarily chosen alloy configuration representing Sample A. The isosurface corresponds to 25% of the respective maximum charge density values. The well boundaries are schematically indicated by dashed lines. Figure 7. Calculated relative radiative lifetime as a function of alloy configuration number. The results for the narrower well system (Sample A) are given by the black squares; data for the wider well system (Sample B) are denoted by the red circles. Figure 8. Contour plot of built-in potential of c-plane AlGaN/GaN QW system representing Sample A for a slice through the the x − z-plane. The z-axis is parallel to the wurtzite c-axis. The white dashed lines schematically indicate the QW interfaces. (a) Random alloy treatment (arbitrarily chosen microscopic configuration) and (b) result from the virtual crystal approximation (VCA).

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