Facile and in-situ spray deposition of SnO2 - reduced graphene oxide heterostructure sensor devices

• Published in: Journal of physics communications Vol. 3; no. 1
• Main Author: Kamble, Vinayak B
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.01.2019
• Subjects: gas sensor; Graphene; heterostructure; spray pyrolysis; tin oxide
• ISSN: 2399-6528
• DOI: 10.1088/2399-6528/aafe35

A facile and economic solution based technique is developed for the deposition of SnO2-Reduced Graphene Oxide (RGO) heterostructure thin films. The single step deposition process leads to uniformly dispersed SnO2 nanocrystallites on well exfoliated RGO sheets as confirmed by x-ray diffraction, Raman spectroscopy and transmission electron microscopy investigations. The response to NO2 gas at room temperature (25 °C) is studied. The interface between n-type SnO2 and p-type RGO flakes forms a hetrostrcuture barrier, which enhances the native sensitivity of pristine RGO towards toxic gases like NO2. The technique allows controlling the density of SnO2 nanoparticles (∼3 nm in size) attached to the RGO flakes and thereby enhancing the response of the heterostructure sensor device. The highest SnO2 loading shows a 14 fold increase in response to 200 ppm of NO2 and a response time as low as 5 s compared to that of ∼200 s for bare RGO films.