Copper Oxide-Loaded Tin Dioxide Thin Film for Detection of Dilute Hydrogen Sulfide

Abstract

The H2S sensing characteristics of SnO2 thin films loaded with CuO were found to be much improved by reducing the film thickness. A 40-nm-thick film showed sensitivity as high as 20000 and 2000 to 1.5 and 0.3 ppm H 2 S in air, respectively, at 200° C, while the rate of response to 0.3 ppm H 2 S was rather slow.

Heterocontact type CuO-modified SnO2 sensor for the detection of a ppm level H2S gas at room temperature

“…The p-n heterocontact concept is used in the present investigation, instead of adsorption-desorption mechanism, which was introduced in 1979 and has been applied as humidity sensors, liquid sensors and gas sensors [27][28][29][30][31][32][33][34]. The heterocontact concept was found to be very effective for the H 2 S gas sensing at room temperature.…”

CuO-doped BSST thick film resistors for ppb level H2S gas sensing at room temperature

“…Concerning the detection of dilute H 2 S less than 1 ppm, thin film or thick film sensors using CuO-SnO 2 [5,6], WO 3 [7][8][9], and CuO-doped SnO 2 [10] have been reported to show excellent performance. Recently, nanophased WO 3 -based H 2 S gas sensors have been reported [11] for the detection of ppb-level H 2 S. It is reported that CuO-surface modified BSST (using dipping technique) sensors respond to 100 ppm H 2 S gas at 300 • C. Instead of such modification of the film surface, BSST was doped with CuO in this article.…”

“…The p-n heterocontact concept was used in the present investigation [18][19][20][21][22][23][24][25][26][27]. There is an intrinsic difference in the behavior between the heterocontact type sensors and the sensors based on catalytic oxidation/reduction of gas molecules.…”

Enhanced catalytic activity of ultrathin cuo islands on SnO/sub 2/ films for fast response H/sub 2/S gas sensors

“…Sintered pastes [5], thick [6], and thin-film structures using mixed -powders, Cubilayers [7], and -hetero-contacts [8], chemically-fixed on [9], [10] have been extensively investigated. Some of those sensor materials offer a high sensitivity but response time is often found to be slow (3 to 175 min) [2]- [5], [8], [11]- [13] and a faster response time (15 to 180 s) has been reported only for a higher concentrations of gas [6], [7], [9], [10]. The high sensitivity of -doped sensors has been attributed to the electronic interaction between the -type and the -type polycrystalline [14] and the effect of gas in reducing the barrier height [15].…”