The self-assembled type-II GaSb quantum dots (QDs) were successfully grown on semi-insulting GaAs (100) substrate by the liquid phase epitaxy (LPE) technique with growth temperature ranging from 520 to 580 oC. The morphology of GaSb QDs including size, shape and density was investigated by atomic force microscopy measurement and scanning electron microscope measurement, respectively. The cap layer with scores of nanometers, which is characterized by Profile-system, is obtained for the photoluminescence measurement and device fabrication.
High-quality InAs1-xSbx films with x=0.06 have been successfully grown on InAs (100) substrates by liquid phase epitaxy. Two methods are used to characterize the electrical properties of InAsSb film. One is to grow InAsSb epilayer on p-type InAs substrate, which, in combination with the n-type epilayer, forms a p-n junction to prevent the parallel conduction from the substrate. The other is that both the conductive InAs substrate and the dislocation layer between InAs and InAsSb are removed completely by chemical mechanical polishing method to get InAsSb film glued onto insulating sapphire substrate. The influence of conductive InAs substrate on the electrical properties of InAsSb film is eliminated effectively.
Single crystalline InAs0.016Sb0.984 film has been successfully grown on (100) InSb substrate by LPE method. A large supercooling (ΔT = 15 °C) had been used to prevent substrate from dissolving into the epilayer. High resolution X-ray diffraction (HRXRD) measurement was used to characterize the crystal quality of the film. Only (200) and (400) peaks were observed from the XRD spectrum, indicating that the film was single crystalline with (100) orientation. The Fourier transform infrared (FTIR) transmission spectrum of the film at room temperature revealed 7.77 μm cut-off wavelength of the film. The lattice dynamics of the epilayer was studied by Raman scattering, suggests two-mode behavior of the optical phonons.