1. Observing visible-range photoluminescence in GaAs nanowires modified by laser irradiation
- Author
-
Prokhor A. Alekseev, Alexander N. Smirnov, V. Yu. Davydov, V. L. Berkovits, Mikhail S. Dunaevskiy, and Demid A. Kirilenko
- Subjects
Physics ,Photoluminescence ,Condensed Matter - Mesoscale and Nanoscale Physics ,Nanowire ,FOS: Physical sciences ,General Physics and Astronomy ,Heterojunction ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Molecular physics ,Amorphous solid ,symbols.namesake ,Nanocrystal ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,0103 physical sciences ,symbols ,010306 general physics ,0210 nano-technology ,Spectroscopy ,Raman scattering ,Wurtzite crystal structure - Abstract
We study structural and chemical transformations induced by focused laser beam in GaAs nanowires with axial zinc-blende/wurtzite (ZB/WZ) heterostucture. The experiments are performed using a combination of transmission electron microscopy, energy-dispersive X-ray spectroscopy, Raman scattering, and photoluminescence spectroscopy. For the both components of heterostructure, laser irradiation under atmospheric air is found to produce a double surface layer which is composed of crystalline arsenic and of amorphous GaO$_{x}$. The latter compound is responsible for appearance of a peak at 1.76 eV in photoluminescence spectra of GaAs nanowires. Under increased laser power density, due to sample heating, evaporation of the surface crystalline arsenic and formation of $\beta$-Ga$_{2}$O$_{3}$ nanocrystals proceed on surface of the zinc-blende part of nanowire. The formed nanocrystals reveal a photoluminescence band in visible range of 1.7-2.4 eV. At the same power density for wurtzite part of the nanowire, total amorphization with formation of $\beta$-Ga$_{2}$O$_{3}$ nanocrystals occurs. Observed transformation of WZ-GaAs to $\beta$-Ga$_{2}$O$_{3}$ nanocrystals presents an available way for creation of axial and radial heterostuctures ZB-GaAs/$\beta$-Ga$_{2}$O$_{3}$ for optoelectronic and photonic applications., Comment: 12 pages, 5 figures
- Published
- 2017