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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 Δa/a = -4.1 x 10-4 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. Plasmonphonon 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. [ABSTRACT FROM AUTHOR]

Colloidal gold nanoparticles have been used as biomaterials since the 1970's. The main goal of developing biological sensors is to identify a number of human diseases and infections with high specificity and sensibility. Two of the most used methods to fabricate biofilms are the Langmuir-Blodgett and the Self-Assembled Monolayer techniques, which are used to obtain homogenous organic and inorganic monolayer films and thin films of organic compounds, respectively. We describe the fabrication of ring-structure colloidal gold nanofilms using both methods. Nanofilms were further characterized by X-Ray Diffraction, Fourier Transformed Infrared Spectroscopy, Ultraviolet-Visible Spectroscopy, and Atomic Force Microscopy. [ABSTRACT FROM AUTHOR]

A set of GaxIn1-xAsySb1-y quaternary layers were grown on (100) GaSb substrates using the liquid phase epitaxy technique (LPE). These layers were doped with tellurium and were characterized by Raman, Photoluminescence (PL) spectroscopy, and Secondary Ion Mass Spectroscopy (SIMS). Several optical modes were identified by performing Raman spectroscopy characterization at room temperature and observing the effect of the impurity concentration on the Raman mode frequencies. From secondary ion mass spectrometry the concentrations of Te in the liquid solutions and the electron densities present in the layers were obtained. Finally, these last results were compared with those obtained from low temperature photoluminescence spectroscopy measurements at low temperatures on this set of samples. [ABSTRACT FROM AUTHOR]

InP-In 2 O 3 colloidal quantum dots (QDs) synthesized by a single-step chemical method without injection of hot precursors (one-pot) were investigated. Specifically, the effect of the tris(trimethylsilyl)phosphine, P(TMS) 3 , precursor concentration on the QDs properties was studied to effectively control the size and shape of the samples with a minimum size dispersion. The effect of the P(TMS) 3 precursor concentration on the optical, structural, chemical surface, and electronic properties of InP-In 2 O 3 QDs is discussed. The absorption spectra of InP-In 2 O 3 colloids, obtained by both UV-Vis spectrophotometry and photoacoustic spectroscopy, showed a red-shift in the high-energy regime as the concentration of the P(TMS) 3 increased. In addition, these results were used to determine the band-gap energy of the InP-In 2 O 3 nanoparticles, which changed between 2.0 and 2.9 eV. This was confirmed by Photoluminescence spectroscopy, where a broad-band emission displayed from 2.0 to 2.9 eV is associated with the excitonic transition of the InP and In 2 O 3 QDs. In 2 O 3 and InP QDs with diameters ranging approximately from 8 to 10 nm and 6 to 9 nm were respectively found by HR-TEM. The formation of the InP and In 2 O 3 phases was confirmed by X-ray Photoelectron Spectroscopy., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2020 Elsevier B.V. All rights reserved.)