Sg. Ansari et al., CHARACTERIZATION OF SNO2-BASED H-2 GAS SENSORS FABRICATED BY DIFFERENT DEPOSITION TECHNIQUES, Journal of materials science. Materials in electronics, 8(1), 1997, pp. 23-27
Thick and thin films of SnO2 are extensively used for resistive gas se
nsors. Characteristics are compared for films produced by four differe
nt techniques - chemical vapour deposition (CVD), spray pyrolysis, vac
uum evaporation and screen printing. The films are characterized for H
p sensing only, using a static measurement system to investigate their
temperature selectivity. The samples are tested at a concentration of
300 p.p.m. H-2 gas, a typical value for comparison. No selective peak
is observed for CVD and spray deposited samples, and the selective pe
ak for vacuum evaporated samples has a low sensitivity. But the select
ive peak for screen printed samples has a sensitivity of 55% (delta R/
R(air)). And what is more, the screen printed samples have a repeatabl
e response.