Study of the Sorption Properties of Ge₂₀Se₈₀ Thin Films for NO₂ Gas Sensing

Authors

Ping Chen, Boise State UniversityFollow
Maria Mitkova, Boise State UniversityFollow
Dmitri A. Tenne, Boise State UniversityFollow
Kasandra Wolf, Boise State University
Velichka Georgieva, Bulgarian Academy of Sciences
Lazar Vergov, Bulgarian Academy of Sciences

Document Type

Article

Publication Date

12-15-2012

DOI

http://dx.doi.org/10.1016/j.tsf.2012.09.077

Abstract

In this study we investigated the sorption ability of Ge₂₀Se₈₀ thin films applied as active layers of quartz crystal microbalance for NO₂ gas sensing. To identify the chalcogenide system appropriate for gas sensing, we provided data for the packing fraction of a number of chalcogenide systems and discussed their suitability. We performed Raman spectroscopy, X-ray photoelectron spectroscopy and atom force microscopy measurements on the thin films both before and after gas absorption, which showed that the introduced gas molecules interact electrostatically with the chalcogen atoms of the host material and initiate some degree of structural changes in it. The weight change due to NO₂ gas absorption was measured by the frequency change of the resonator. The absorbed mass increased monotonically with the thickness of chalcogenide films and the NO₂ gas concentration. At the conditions of our experiment, up to 11.4 ng of the gas was absorbed into 200 nm thick Ge₂₀Se₈₀ film at 5000 ppm NO₂ concentration. The process of gas molecules absorption is found irreversible at the purging conditions.

Publication Information

Chen, Ping; Mitkova, Maria; Tenne, Dmitri A.; Wolf, Kasandra; Georgieva, Velichka; and Vergov, Lazar. (2012). "Study of the Sorption Properties of Ge₂₀Se₈₀ Thin Films for NO₂ Gas Sensing". Thin Solid Films, 525141-147.