Modeling the Conduction Mechanism in Chemoresistive Gas Sensor Based on Single-Crystalline Sn₃O₄ Nanobelts: A Phenomenological In Operando Investigation

Author(s)

Suman, Pedro H. ; Junker, Benjamin ; Weimar, Udo ; Orlandi, Marcelo O. ; Barsan, Nicolae

• Document type: Journal article
• Source: ACS SENSORS; v. 9, n. 1, p. 8-pg., 2024-01-05.

Abstract

Investigating the sensing mechanisms in semiconducting metal oxide (SMOx) gas sensors is essential for optimizing their performance across a wide range of potential applications. Despite significant progress in the field, there are still many gaps in comprehending the phenomenological processes occurring in one-dimensional (1D) nanostructures. This article presents the first insights into the conduction mechanism of chemoresistive gas sensors based on single-crystalline Sn3O4 nanobelts using the operando Kelvin Probe technique. From this approach, direct current (DC) electrical resistance and work function changes were simultaneously measured in different working conditions, and a correlation between the conductance and the surface band bending was established. Appropriate modeling was proposed, and the results revealed that the conduction mechanism in the single-crystalline one-dimensional nanostructures closely aligns with the behavior observed in single-crystalline epitaxial layers rather than in polycrystalline grains. Based on this assumption, relevant parameters were further estimated, including Debye length, concentration of free charge carriers, effective density of states in the conduction band, and position of the Fermi level. Overall, this study provides an effective contribution to understanding the role of surface chemistry in the transduction of the electrical signal generated from gas adsorption in single-crystalline one-dimensional nanostructures. (AU)

• FAPESP's process: 17/24839-0 - Nanoelectronics and nanoscale electrochemistry: fundaments and applications
• Grantee: Paulo Roberto Bueno
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 19/26333-2 - Investigation of the gas sensing performance of FET devices at work: modeling the conduction mechanisms in 1D semiconducting metal oxide nanostructures by operando techniques
• Grantee: Pedro Henrique Suman
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 17/26219-0 - Study of Single Element Chemical Sensor Devices based on Semiconducting Metal Oxide Materials
• Grantee: Marcelo Ornaghi Orlandi
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/20808-0 - Field-effect transistors (FET) based on 1D semiconducting nanostructures: impact of the electrical signal modulation on the gas sensor performance
• Grantee: Pedro Henrique Suman
• Support Opportunities: Scholarships in Brazil - Post-Doctoral