Journal
JOURNAL OF COLLOID AND INTERFACE SCIENCE
Volume 503, Issue -, Pages 150-158Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.jcis.2017.04.055
Keywords
Multilayered micro/nanostructured porous thin films; UV irradiation; Gas sensing responses; Effects of porous structure and film thickness
Categories
Funding
- Natural Science Foundation of China [11374303, 51471161, 11574313]
- CAS-SAFEA International Partnership Program for Creative Research Teams
Ask authors/readers for more resources
The structure and thickness of the chemiresistive thin films can significantly affect their gas sensing performances for the heating-typed sensors. Under light irradiation, however, their influences are still to be addressed. In present paper, the multilayered ZnO porous thin films with different (three types) micro/nanostructures and controllable thickness are fabricated via layer by layer construction of the self-assembled colloidal-layers. The structural and thickness effects of such films on the gas sensing performances to NO2 under ultraviolet (UV) illumination are experimentally studied. It has been found that under UV irradiation, the responses of the ZnO porous thin films to NO2 increase upto the maxima with the rising film thickness. Further increasing the thickness would lead to the insignificantly or gradually decreasing responses. The film thicknesses corresponding to the maximal responses are associated with the porous structures and the porosity of the thin films. The films with the higher porosity would lead to the higher maximal responses and the larger corresponding film-thicknesses, or vice versa. Such thickness and porous-structure dependences of the responses are attributed to the ever-decaying light intensity (and hence ever-decreasing photo-generated carrier concentration) in the films along the depth from the films' surface. This study is of importance in design and development of the light illuminating typed gas sensing devices with high performances. (C) 2017 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available