Diffuse Reflectance Infrared Fourier Transform (DRIFT)-spectroscopy is one of the most advanced and effective technologies for examining the composition of rough-surfaced solid samples such as nanostructured semiconducting films, which constitute the functional layer in chemoresistive gas sensors. An operando approach has been used in the present work to combine DRIFT spectroscopy and electrical characterization of thick-film sensors based on SnO2, (Sn,Ti)xO2 and a new metal-oxide solid solution, namely (Sn,Ti,Nb)xO2. The aim is to shed light into the sensing mechanism of the analyzed materials and pave the way to future optimized metal-oxides. The investigation focused on ethanol sensing and the peculiar negligible effect of relative humidity (RH%) on the film resistance, which improved sensor accuracy and facilitated calibrations. For instance, the higher response level to 22 RH% of SnO2 than that of (Sn,Ti)xO2 and (Sn,Ti,Nb)xO2 (Fig. 1a) was the result of different surface interactions with H2O molecules, as highlighted by the bands that appeared in the Operando DRIFT apparent absorbance (AB) spectra collected while the sensors were exposed to humid air (Fig. 1b).
Operando DRIFT-Spectroscopy on a Ternary Oxides Solid Solution-Based Chemoresistive Gas Sensor
Elena Spagnoli
;Barbara Fabbri;Arianna Rossi;Vincenzo Guidi
2023
Abstract
Diffuse Reflectance Infrared Fourier Transform (DRIFT)-spectroscopy is one of the most advanced and effective technologies for examining the composition of rough-surfaced solid samples such as nanostructured semiconducting films, which constitute the functional layer in chemoresistive gas sensors. An operando approach has been used in the present work to combine DRIFT spectroscopy and electrical characterization of thick-film sensors based on SnO2, (Sn,Ti)xO2 and a new metal-oxide solid solution, namely (Sn,Ti,Nb)xO2. The aim is to shed light into the sensing mechanism of the analyzed materials and pave the way to future optimized metal-oxides. The investigation focused on ethanol sensing and the peculiar negligible effect of relative humidity (RH%) on the film resistance, which improved sensor accuracy and facilitated calibrations. For instance, the higher response level to 22 RH% of SnO2 than that of (Sn,Ti)xO2 and (Sn,Ti,Nb)xO2 (Fig. 1a) was the result of different surface interactions with H2O molecules, as highlighted by the bands that appeared in the Operando DRIFT apparent absorbance (AB) spectra collected while the sensors were exposed to humid air (Fig. 1b).I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
