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AlxGa1-xN epilayers with a wide AI composition range (0.2≤x≤0.68) were grown on AIN/sapphire templates by low-pressure metalorganic chemical vapour deposition (LP-MOCVD).X-ray diffraction results reveal that both the (0002) and (1015) full widths at half-maximum (FWHM) of the AlxGa1-xN epilayer decrease with increasing Al composition due to the smaller lattice mismatch to the A1N template.However,the surface morphology becomes rougher with increasing AI composition due to the weak migration ability of Al atoms.Low temperature photoluminescence (PL) spectra show pronounced near band edge (NBE) emission and the NBE FWHM becomes broader with increasing Al composition mainly caused by alloy disorder.Meanwhile,possible causes of the low energy peaks in the PL spectra are discussed.