MOLECULAR-BEAM-EPITAXIAL GROWTH OF III-VI LAYERED SEMICONDUCTOR GASE ON AMORPHOUS SIO2

Crystalline thin films of III-VI layered semiconductor GaSe have been grown on amorphous SiO2 substrates using molecular-beam-epitaxy techniques. This attests possible formation of a crystalline/noncrystalline heterostructure when inactive GaSe surfaces are involved. Reflection-high-energy-electron-diffraction and (00l) x-ray diffraction results show in-plane and stacking ordering, respectively. Although the coexistence of multiple crystalline domains in plane is suggested, the photoluminescence spectra are comparable to those of a GaSe bulk single crystal. Excitonic emission with the full-width at the half magnitude of 5 nm (19 meV) is observed at 591 nm (2.10 eV) at 77 K.