Title

Thickness dependent self limiting 1-D tin oxide nanowire arrays by nanosecond pulsed laser irradiation

Authors

Authors

N. Shirato; J. Strader; A. Kumar; A. Vincent; P. Zhang; A. Karakoti; P. Nacchimuthu; H. J. Cho; S. Seal;R. Kalyanaraman

Comments

Authors: contact us about adding a copy of your work at STARS@ucf.edu

Abbreviated Journal Title

Nanoscale

Keywords

HYDROGEN SENSOR; ROOM-TEMPERATURE; FUSED-SILICA; THIN-FILM; SURFACE; NANOSENSORS; ABSORPTION; SIZE; Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials; Science, Multidisciplinary; Physics, Applied

Abstract

Fast, sensitive and discriminating detection of hydrogen at room temperature is crucial for storage, transportation, and distribution of hydrogen as an energy source. One dimensional nanowires of SnO2 are potential candidates for improved H-2 sensor performance. The single directional conducting continuous nanowires can decrease electrical noise, and their large active surface area could improve the response and recovery time of the sensor. In this work we discuss synthesis and characterization of nanowire arrays made using nanosecond ultraviolet wavelength (266 nm) laser interference processing of ultrathin SnO2 films on SiO2 substrates. The laser energy was chosen to be above the melting point of the films. The results show that the final nanowire formation is dominated by preferential evaporation as compared to thermocapillary flow. The nanowire height (and hence wire aspect ratio) increased with increasing initial film thickness h(0) and with increasing laser energy density E-o. Furthermore, a self-limiting effect was observed where-in the wire formation ceased at a specific final remaining thickness of SnO2 that was almost independent of h(0) for a given E-o. To understand these effects, finite element modeling of the nanoscale laser heating was performed. This showed that the temperature rise under laser heating was a strong non-monotonic function of film thickness. As a result, the preferential evaporation rate varies as wire formation occurs, eventually leading to a shut-off of evaporation at a characteristic thickness. This results in the stoppage of wire formation. This combination of nanosecond pulsed laser experiments and thermal modeling shows that several unique synthesis approaches can be utilized to control the nanowire characteristics.

Journal Title

Nanoscale

Volume

3

Issue/Number

3

Publication Date

1-1-2011

Document Type

Article

Language

English

First Page

1090

Last Page

1101

WOS Identifier

WOS:000288218300047

ISSN

2040-3364

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