Epitaxial Growth of GaSe Films by Molecular Beam Epitaxy on GaAs(111), (001) and (112) Substrates

We have successfully grown epitaxial GaSe films on GaAs(111), (001) and (112) by molecular beam epitaxy. On the GaAs(111) substrate, the c -axis of the GaSe layer was perpendicular to the substrate surface, while each unit layer of GaSe was inclined on GaAs(001) and (112) substrates when the growth temperatures were higher than 500°C at high beam fluxes of Ga and Se. Furthermore, we could detect strong photoluminescence (PL) emission from the GaSe films grown on GaAs(001) and (112) substrates. This result suggests that crystal quality was improved by growth through chemical bonding at a higher growth temperature.