Growth and characterization of gallium arsenide on sapphire by molecular beam epitaxy

Gallium Arsenide thin films have been successfully grown onto (1102) sapphire substrates by Molecular Beam Epitaxy methods using a graded growth procedure. The initial layers of GaAs were grown at lower growth rates and at lower substrate temperatures, followed by a thicker GaAs layer grown at usual growth rate of 1 μm/h. The films grown at temperature of 585 °C show good surface morphology. Silicon doped GaAs films exhibit n type conductivity and show low temperature photoluminescence band with peak energy at 1.502 eV and line width of about 42 meV.