Optimization of the hydrogen response characteristics of halogen-doped SnO2

Petros-Panagis Filippatos; Rohit Sharma; Anastasia Soultati; Nikolaos Kelaidis; Christos Petaroudis; Anastasia-Antonia Alivisatou; Charalampos Drivas; Stella Kennou; Stavros-Richard G Christopoulos; Dimitris Davazoglou; Maria Vasilopoulou; Alexander Chroneos

doi:10.1038/s41598-023-29312-6

Optimization of the hydrogen response characteristics of halogen-doped SnO₂

Sci Rep. 2023 Feb 13;13(1):2524. doi: 10.1038/s41598-023-29312-6.

Authors

Affiliations

¹ Institute of Nanoscience and Nanotechnology (INN), National Center for Scientific Research Demokritos, Agia Paraskevi, 15341, Athens, Greece. petpanfilippatos@gmail.com.
² Faculty of Engineering, Environment and Computing, Coventry University, Priory Street, Coventry, CV1 5FB, UK. petpanfilippatos@gmail.com.
³ Faculty of Engineering, Environment and Computing, Coventry University, Priory Street, Coventry, CV1 5FB, UK.
⁴ Institute of Nanoscience and Nanotechnology (INN), National Center for Scientific Research Demokritos, Agia Paraskevi, 15341, Athens, Greece.
⁵ Department of Electrical and Electronics Engineering, Faculty of Engineering, University of West Attica, Campus 2, No. 250, Thivon Str., 12244, Athens, Greece.
⁶ School of Mining and Metallurgical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780, Athens, Greece.
⁷ Department of Chemical Engineering, University of Patras, 26504, Patras, Greece.
⁸ Department of Electrical and Computer Engineering, University of Thessaly, 38221, Volos, Greece. alexander.chroneos@imperial.ac.uk.
⁹ Department of Materials, Imperial College, London, SW7 2AZ, UK. alexander.chroneos@imperial.ac.uk.

Abstract

The increasing demand for efficient sensing devices with facile low-cost fabrication has attracted a lot of scientific research effort in the recent years. In particular, the scientific community aims to develop new candidate materials suitable for energy-related devices, such as sensors and photovoltaics or clean energy applications such as hydrogen production. One of the most prominent methods to improve materials functionality and performance is doping key device component(s). This paper aims to examine in detail, both from a theoretical and an experimental point of view, the effect of halogen doping on the properties of tin dioxide (SnO₂) and provide a deeper understanding on the atomic scale mechanisms with respect to their potential applications in sensors. Density Functional Theory (DFT) calculations are used to examine the defect processes, the electronic structure and the thermodynamical properties of halogen-doped SnO₂. Calculations show that halogen doping reduces the oxide bandgap by creating gap states which agree well with our experimental data. The crystallinity and morphology of the samples is also altered. The synergy of these effects results in a significant improvement of the gas-sensing response. This work demonstrates for the first time a complete theoretical and experimental characterization of halogen-doped SnO₂ and investigates the possible responsible mechanisms. Our results illustrate that halogen doping is a low-cost method that significantly enhances the room temperature response of SnO₂.