List of figures
LIST OF FIGURES
Figure 1.1. The atom arrangement in wurtzite and zincblende structures………..….05 Figure 1.2. The growth diagram for cubic GaN grown by MBE. Three growth regimes under Ga
stable, N stable and Ga droplets were defined with a constant N flux………08 Figure 1.3. A typical PL spectrum for a thin (~0.8μm) cubic GaN layer measured at 4.2K...11 Figure 1.4. A typical PL spectrum for a thick (~1.9μm) cubic GaN layer at 4.2K…………..14 Figure 1.5. Crystal Structures of ScN………..21 Figure 1.6. The electronic band structures of rocksalt ScN……….23
Figure 1.7. Calculated phonon dispersions and density of states for rocksalt ScN. Experimental data (filled circles)………..24
Figure 2.1. Schematic representation of the real-space pseudopotential. The solid line represents
the pseudopotential and the dashed line represents the real potential……….37
Figure 2.2. Schematic representation of the pseudowavefunction. The solid line represents the
pseudowavefunction and the dashed line represents the real wavefunction……….37 Figure 2.3. The Monte-Carlo algorithm used for the fitting of the pseudopotential
parameters……….45 Figure 2.4. High symmetry points in the Brillouin zone for the zincblende structure……….46 Figure 2.5. The band structures for zincblende structure GaN. The dashed lines are calculated using
the first principles code VASP and the solid lines are calculated using the empirical pseudopotential method. The diamonds represent the targets used in the fitting procedure…47
Figure 3.1. Direct band gap energy in ScxGa1–xN as a function of Sc content………....54
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List of figures
Figure 3.2. Direct ( EΓΓ ) (blue curve) and indirect ( EΓX ) (red curve) and ( EΓL ) (green curve) band gap energies in ScxGa1–xN as a function of Sc content………55 Figure 3.3. Valence band width in ScxGa1–xN ternary alloys as a function of Sc content…...57 Figure 3.4. Antisymmetric band gap energy in ScxGa1–xN as a function of Sc content ……..58 Figure 3.5. Ionicity factor in ScxGa1–xN as a function of Sc content ………...58 Figure 3.6. Effective mass of the electron in ScxGa1–xN as a function of Sc content………...60 Figure 3.7. Effective mass of heavy hole in ScxGa1–xN as a function of Sc content…………60 Figure 3.8. the refractive indices of the dilute nitride alloys in ScxGa1–xN as a function of Sc content
………..62
Figure 3.9. The static and high-frequency dielectric constants in ScxGa1–xN as a function of Sc
content………..63
Figure 3.10. Transverse effective charge in ScxGa1–xN as a function of Sc content………....65
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