Predicting surface modification of InAs nanowires on laser irradiation using transient thermal simulation and time evolution of Raman spectra

In this work, role of temperature simulation is investigated for predicting surface modification of InAs nanowire (NW) using laser irradiation. The surface modification is monitored by Raman spectroscopy. We first establish correlation between simulated temperatures at the surface of an InAs nanowire (NW) with time evolution of Raman spectra on laser irradiation. Transient thermal simulations are performed with ANSYS software using finite element method, considering 3D geometry of the irradiation setup. In the systematic study of laser irradiation (laser power densities similar to 30-636 kW/cm(2)) over time duration of similar to 8 min, the simulated temperature is found to corroborate well with the corresponding oxidation processes e.g. weak (WP), intermediate (IP) and strong (SP), occurring on the surface of InAs nanowire under various laser irradiation conditions. The predictability of the methodology was then investigated by applying it to random conditions of NW like diameter, aspect ratio and laser power density etc. for i) NWs found in the same sample and ii) InAs NWs grown elsewhere and transferred on other Si substrate. The study establishes predictability of various oxidation processes for given NWdimensions, laser power density and irradiation time, thereby ascertaining importance and applicability of the temperature simulation in controlling surface modification of randomly chosen InAs NWs, as per the requirement for device applications. (C) 2017 Elsevier B.V. All rights reserved.