Optical Properties of GaSb Nanofibers
1 School of Physical Electronics, University of Electronic Science and Technology of China, 610054 Chengdu, China
2 Department of Materials Science and Engineering, University of Michigan, 48109 Ann Arbor, MI, USA
3 Department of Electrical Engineering and Computer Science, University of Michigan, 48109 Ann Arbor, MI, USA
4 Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 48109 Ann Arbor, MI, USA
Nanoscale Res Lett 2011, 6:6 doi:10.1007/s11671-010-9739-2Published: 21 August 2010
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.