Diameter dependent heating in GaAs nanowires

Abstract

The photo-thermal properties of vertically etched gallium arsenide nanowire arrays are examined using Raman spectroscopy. The nanowires are arranged in square lattices with a constant pitch of 400 nm, and diameters ranging from 50 to 155 nm. The arrays were illuminated using a 532 nm laser with an incident energy density of 10 W/mm 2 . Nanowire temperatures were highly dependent on the nanowire diameter, and were determined by measuring the spectral redshift for both TO and LO phonons. The highest temperatures were observed for the 95 nm diameter nanowires, whose top facets and sidewalls heated up to 600 K and 440 K, respectively, and decreased significantly for the smaller or larger diameters studied. The findings also demonstrate that a photonic lattice consisting of vertically oriented GaAs nanowires allows for optimization of the photo-thermal effect.978-1-4799-5622-7/$31.00 ©2014 IEEE

Diameter Control of GaSb Nanowires Revealed by In Situ Environmental Transmission Electron Microscopy

“…Nanowire diameter has been shown to have a significant impact on the electrical, thermal, and optical properties of nanowires. − Several studies have also demonstrated that modulated nanowire diameters can enhance properties such as absorption by more efficient light trapping and enhanced thermoelectric conversion. This highlights the importance of fundamental knowledge connecting the growth conditions and resulting nanowire morphology. − The correlation between growth conditions and nanowire diameter in GaSb and InSb nanowires has been explored in earlier studies. ,, However, due to the inability to observe growth dynamics and determine seed particle composition during growth, a crucial step connecting the precursor pressures used and the resulting nanowire diameter is missing.…”