The effect of the gaseous atmosphere in the growth of gallium arsenide (GaAs) films was studied. The films have been grown by close-spaced vapor transport (CSVT) technique in a home-made hot filament chemical vapor deposition (HFCVD) reactor using molecular hydrogen and molecular nitrogen as the transport agent. An important point about the gaseous atmosphere is the ease in creating volatile compounds when it makes contact with the GaAs source, this favors the transport of material in a CSVT system. Chemical reactions are proposed in order to understand the significant difference produced from the gaseous atmosphere. The films grown with hydrogen are (almost) continuous and have homogeneous layers with preferential orientation (111). The films grown with nitrogen are granular and rough layers with the coexistence of the orientations (111), (220) and (311) in the crystals. The incorporation of impurities in the films was corroborated by energy dispersive spectroscopy (EDS) showing traces of oxygen and nitrogen for the case of the samples obtained with nitrogen. Films grown in a hydrogen atmosphere show a higher band gap than those grown in a nitrogen atmosphere. With the results of XRD and micro-Raman we observe a displacement and broadening of the peaks, characteristic of a structural disorder. The calculations of the FWHM allow us to observe the crystallinity degree and determine an approximate crystallite size using the Scherrer’s equation.

We report the growth of In0.145Ga0.855As0.132Sb0.868 layers on GaSb(100) substrates by the liquid phase epitaxy (LPE) technique using the ramp-cooling method. We achieved a near-lattice-matched epitaxial growth with a lattice mismatch of between the quaternary layer and GaSb(100) substrate due to optimal growth parameters. Aberration-corrected scanning transmission electron microscope (AC-STEM) confirmed the high crystalline quality of the quaternary layer and the low lattice mismatch in the heterostructure, without the presence of linear or planar defects. Also, the Secondary Ion Mass Spectrometry (SIMS) technique evidenced a uniform distribution of the atomic elements along the quaternary layer and an abrupt interface between the In0.145Ga0.855As0.132Sb0.868 layer and the GaSb substrate. Plasmon-phonon interactions were observed by Raman spectroscopy indicating that the crystalline quality increases at greater depth in the sample with respect to the surface. The quaternary layer presented a uniform and flat morphology, and luminescence emission attributed to the recombination of bound exciton states at 641 meV. The structural, chemical, and optical properties of the In0.145Ga0.855As0.132Sb0.868 layer demonstrated that it could be auspicious material for infrared range optoelectronic applications. Likewise, the LPE technique successfully shows that it should be used to grow near-lattice-matched heterostructures.

GaSb nanostructures were grown on Si(111) substrates using graphene (G) as a buffer interlayer by the close-spaced vapor transport (CSVT) technique at different growth temperatures. Raman spectroscopy confirmed the growth of GaSb through the observation of its characteristic longitudinal optical (LO) and transverse optical (TO) phonon modes, together with Sb–Sb vibrational features associated with excess antimony. In addition, temperature-dependent Raman measurements evidenced irreversible structural modifications at elevated measurement temperatures, reflected in changes in the Sb–Sb and TO vibrational modes. X-ray photoelectron spectroscopy (XPS) revealed the presence of Ga–Sb bonds, while High-Resolution Transmission Electron Microscopy (HR-TEM) showed that the nanostructures exhibit preferred crystallographic orientation along the (111) and (200) planes. Scanning Electron Microscopy (SEM) further revealed a clear temperature-dependent morphological change from nanocolumnar structures at lower growth temperatures to coalesced clustered morphologies at higher temperatures. To gain deeper insight into the growth mechanism, first-principles calculations were performed, indicating that an Sb layer rotated by 30° in-plane with respect to the G/Si(111) substrate reduces the surface energy and favors the crystallographic orientations observed by HR-TEM. These findings demonstrate a viable route for the growth of GaSb nanostructures on G/Si(111) substrates and highlight the significant potential of graphene-assisted van der Waals integration of III–V semiconductors with silicon for future optoelectronic devices and sensing applications.