Optical Properties of GaSb Nanofibers

Abstract

Amorphous GaSb nanofibers were obtained by ion beam irradiation of bulk GaSb single-crystal wafers, resulting in fibers with diameters of ~20 nm. The Raman spectra and photoluminescence (PL) of the ion irradiation-induced nanofibers before and after annealing were studied. Results show that the Raman intensity of the GaSb LO phonon mode decreased after ion beam irradiation as a result of the formation of the amorphous nanofibers. A new mode is observed at ~155 cm-1 both from the unannealed and annealed GaSb nanofiber samples related to the A1g mode of Sb–Sb bond vibration. Room temperature PL measurements of the annealed nanofibers present a wide feature band at ~1.4–1.6 eV. The room temperature PL properties of the irradiated samples presents a large blue shift compared to bulk GaSb. Annealed nanofibers and annealed nanofibers with Au nanodots present two different PL peaks (400 and 540 nm), both of which may originate from Ga or O vacancies in GaO. The enhanced PL and new band characteristics in nanostructured GaSb suggest that the nanostructured fibers may have unique applications in optoelectronic devices.

Fabrication of Sub-25 nm Diameter GaSb Nanopillar Arrays by Nanoscale Self-Mask Effect

“…For GaSb substrates, two peaks were observed at 230 and 237 cm −1 in Raman spectrum, which can be attributed to transverse optical (TO) phonons and longitudinal optical (LO) phonons. 40,41 For GaSb nanopillar arrays, similar two peaks were observed at 231 and 236 cm −1 in Raman spectrum, indicating high photonics quality of the nanopillar arrays formed by our self-masked etching method. For zinc blendestructured GaAs nanowires with diameter 20 nm, the LO Raman Peak was estimated to be broadened by about 1 cm −1 to the low energy side of the spectrum according to the RCF model based on the estimation from the isotropic form of phonon dispersion relation determined from the neutron scattering data.…”

A simple approach to obtain hybrid Au-loaded polymeric nanoparticles with a tunable metal load

“…This procedure was adopted because it could guarantee a similar load of Au 3+ ions provided that the relative amounts of water and oil could be maintained in each PLGA NP. Similarly to a modified Turkevich procedure, 36 the reduction of Au 3+ ions to Au could be activated at the desired time by using a temperature increase, since at room temperature the Au 3+ payload of each PLGA NP is stable enough to avoid reduction by citrate ions. Since PLGA 50 : 50 has a low vitreous transition temperature, 45–50 °C, 37 40 °C was selected as a suitable temperature to activate the redox reaction while keeping sufficient polymer rigidity to minimize the outward diffusion of the encapsulated chemicals.…”

The effect of Mn2Sb2 and Mn2Sb secondary phases on magnetism in (GaMn)Sb thin films

“…In the up inset of Fig 2 shows the deconvolution of the pick found at 230 cm -1 Raman shift, characterized by three weak vibrations at 226 cm -1 , 220 cm -1 and 215 cm -1 , which are associated to LO (226 cm -1 ) and TO modes, respectively. TO modes observed in the samples here, can be related with substrate inhomogeneity and imperfections on surface [38]. The presence of phonon modes observed at 141 cm -1 and 108 cm −1 can be related with the incorporation Mn atoms during synthesis process.…”