TY - JOUR
T1 - DFT and experimental interpretations of silicon-based room-temperature NO2 sensors improving humidity independence
AU - Chiang, Fang Yu
AU - Hsiao, Po Hsuan
AU - Wu, Tsung Yen
AU - Dien, Vo Khuong
AU - Lin, Ming Fa
AU - Chen, Chia Yun
N1 - Funding Information:
This work was supported by the National Science and Technology Council of Taiwan under Grant No. 110-2223-E-006-003-MY3 , and Hierarchical Green-Energy Materials ( Hi-GEM ) Research Center, from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) and the Ministry of Science and Technology (MOST 107-3017-F-006 -003 ) in Taiwan.
Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/9/1
Y1 - 2023/9/1
N2 - Insights toward detecting hazardous NO2 gas at room temperature with nearly humidity-independent sensing characteristics has been promisingly envisioned yet rare reports have been addressed. Here, the spatial configurations for favorable NO2 adsorption on the incorporated WOx/Si structures were studied using density functional theory (DFT) calculations. Results reveal that the more negative adsorption energy encountered for NO2 adsorption exists in exposed Si surfaces, which further show the largest magnitude of charge transfer (0.16 e), compared with WOx surfaces (0.08 e), and WOx/Si interfaces (0.02 e) evidenced from Bader charge analysis. To experimentally remedy the correlated sensing performances, incorporations of either dense or distributed WOx nanoparticles on aligned Si nanowires featuring z-scheme band structure were synthesized, where the coupled heterostructures with distributed WOx features display the environmentally stable gas-sensing characteristics by featuring trivial degradation of sensing response of 8.4% under high humidity of 83% compared with average response within humidity range of 24.5–55.2%, and such detection robustness is much superior than other oxide-based NO2-gas sensors in the literature. Examinations of band structures clarify that the rule of Si in such promising NO2 sensors behaves as a bridge that efficiently rectifies the hole flows for synergistically improving room-temperature detection.
AB - Insights toward detecting hazardous NO2 gas at room temperature with nearly humidity-independent sensing characteristics has been promisingly envisioned yet rare reports have been addressed. Here, the spatial configurations for favorable NO2 adsorption on the incorporated WOx/Si structures were studied using density functional theory (DFT) calculations. Results reveal that the more negative adsorption energy encountered for NO2 adsorption exists in exposed Si surfaces, which further show the largest magnitude of charge transfer (0.16 e), compared with WOx surfaces (0.08 e), and WOx/Si interfaces (0.02 e) evidenced from Bader charge analysis. To experimentally remedy the correlated sensing performances, incorporations of either dense or distributed WOx nanoparticles on aligned Si nanowires featuring z-scheme band structure were synthesized, where the coupled heterostructures with distributed WOx features display the environmentally stable gas-sensing characteristics by featuring trivial degradation of sensing response of 8.4% under high humidity of 83% compared with average response within humidity range of 24.5–55.2%, and such detection robustness is much superior than other oxide-based NO2-gas sensors in the literature. Examinations of band structures clarify that the rule of Si in such promising NO2 sensors behaves as a bridge that efficiently rectifies the hole flows for synergistically improving room-temperature detection.
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U2 - 10.1016/j.snb.2023.133996
DO - 10.1016/j.snb.2023.133996
M3 - Article
AN - SCOPUS:85162751038
SN - 0925-4005
VL - 390
JO - Sensors and Actuators B: Chemical
JF - Sensors and Actuators B: Chemical
M1 - 133996
ER -