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Updated: May 23, 2026
10:42
Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing
Published on: March 22, 2019
Hydrocarbon Sensing with LaFeO3-Based Gas Sensors; In-Operando Kelvin Probe Investigation of the Transduction
Ji Hye Choi1, Udo Weimar1, Nicolae Bârsan1
1Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 15, Tübingen 72076, Germany.
ACS Sensors
|May 22, 2026
Summary
This study investigates lanthanum ferrite (LaFeO3) for gas sensors. We reveal how surface species like formates and carbonates impact sensor signals, improving performance through a new conduction model.
Area of Science:
- Materials Science
- Chemical Sensing
- Surface Chemistry
Background:
- Industrial growth necessitates advanced environmental monitoring.
- High-performance gas sensors require novel materials like lanthanum ferrite (LaFeO3).
- LaFeO3 shows promise for hydrocarbon detection due to its surface chemistry.
Purpose of the Study:
- To understand the mechanism linking surface effects to sensor signals in LaFeO3.
- To establish a relationship between sensor resistance and surface band bending.
- To extract electron affinity changes upon gas exposure.
Main Methods:
- Simultaneous in-operando work function changes and DC sensor resistance measurements.
- Development of an adapted conduction model for grain neck geometry.
- Analysis of gas mixtures to observe sensor responses.
Main Results:
- Determined the relationship between sensor resistance and surface band bending.
- Extracted electron affinity changes and identified surface carbonates/bicarbonates as dipoles.
- Confirmed the role of formate species in band bending and determined bulk hole concentration and Fermi level position.
Conclusions:
- The study provides a comprehensive understanding of gas exposure effects on LaFeO3.
- The adapted model enables improved strategies for enhancing gas sensor performance.
- Identified key material properties crucial for sensor optimization.
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