TY - JOUR
T1 - Structural Properties and Sensing Performance of CeYxOy Sensing Films for Electrolyte-Insulator-Semiconductor pH Sensors
AU - Pan, Tung Ming
AU - Wang, Chih Wei
AU - Chen, Ching Yi
N1 - Publisher Copyright:
© The Author(s) 2017.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - In this study we developed CeYx Oy sensing membranes displaying super-Nernstian pH-sensitivity for use in electrolyte-insulator-semiconductor (EIS) pH sensors. We examined the effect of thermal annealing on the structural properties and sensing characteristics of the CeYx Oy sensing membranes deposited through reactive co-sputtering onto Si substrates. X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy revealed the structural, morphological, and chemical features, respectively, of the CeYx Oy films after their annealing at 600-900 °C. Among the tested systems, the CeYx Oy EIS device prepared with annealing at 800 °C exhibited the highest sensitivity (78.15 mV/pH), the lowest hysteresis voltage (1.4 mV), and the lowest drift rate (0.85 mV/h). Presumably, these annealing conditions optimized the stoichiometry of (CeY)O2 in the film and its surface roughness while suppressing silicate formation at the CeYx Oy-Si interface. We attribute the super-Nernstian pH-sensitivity to the incorporation of Y ions in the Ce framework, thereby decreasing the oxidation state Ce (Ce4+ → Ce3+) and resulting in less than one electron transferred per proton in the redox reaction.
AB - In this study we developed CeYx Oy sensing membranes displaying super-Nernstian pH-sensitivity for use in electrolyte-insulator-semiconductor (EIS) pH sensors. We examined the effect of thermal annealing on the structural properties and sensing characteristics of the CeYx Oy sensing membranes deposited through reactive co-sputtering onto Si substrates. X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy revealed the structural, morphological, and chemical features, respectively, of the CeYx Oy films after their annealing at 600-900 °C. Among the tested systems, the CeYx Oy EIS device prepared with annealing at 800 °C exhibited the highest sensitivity (78.15 mV/pH), the lowest hysteresis voltage (1.4 mV), and the lowest drift rate (0.85 mV/h). Presumably, these annealing conditions optimized the stoichiometry of (CeY)O2 in the film and its surface roughness while suppressing silicate formation at the CeYx Oy-Si interface. We attribute the super-Nernstian pH-sensitivity to the incorporation of Y ions in the Ce framework, thereby decreasing the oxidation state Ce (Ce4+ → Ce3+) and resulting in less than one electron transferred per proton in the redox reaction.
UR - http://www.scopus.com/inward/record.url?scp=85020381069&partnerID=8YFLogxK
U2 - 10.1038/s41598-017-03209-7
DO - 10.1038/s41598-017-03209-7
M3 - 文章
C2 - 28592824
AN - SCOPUS:85020381069
SN - 2045-2322
VL - 7
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 2945
ER -