Advantage of heteroepitaxial GaSb thin-film buffer and GaSb dot nucleation layer for GaSb/AlGaSb multiple quantum well structure grown on Si(1 0 0) substrate by molecular beam epitaxy

•MBE was used to grow GaSb buffer and dot nucleation layers on Si(1 0 0).•Epitaxially grown MQW structure showed high quality.•Resulting MQWs were near designed size (8 nm) with very narrow PL peaks.•Properties of GaSb buffer and MQW structure were related to the growth temperature.•GaSb buffer and dot nucleation layers could be applied in production. We grew a GaSb/Al0.3Ga0.7Sb multiple-quantum-well (MQW) structure on a two-inch Si(1 0 0) substrate using a 100-nm-thick heteroepitaxial GaSb thin-film buffer with a nucleation layer of GaSb dots by molecular beam epitaxy (MBE) and evaluated the surface morphology and the photoluminescence (PL) and X-ray diffraction spectra of the MQW structure. The full width at half maximum of the PL spectrum of the GaSb/Al0.3Ga0.7Sb MQW structure was very narrow, although the buffer thickness was much lower than those for previously reported GaSb-based QW structures on Si(1 0 0) substrates. This indicated that the surface of the 100-nm-thick GaSb thin-film buffer was sufficiently flat to form heterostructures and MQWs. The surface roughness and crystalline quality of the GaSb buffer and MQW structure were strongly dependent on the growth temperature; high-performance devices were realized by optimizing the growth temperature. These results showed the advantage and potential applicability of the GaSb/Al0.3Ga0.7Sb MQW structure and the GaSb thin-film buffer with GaSb dots as a nucleation layer grown on Si(1 0 0) substrates.