Enhancing SrCoO FET sensor performance through Sc doping: experimental and theoretical analysis

This study integrates experimental methods with DFT calculations to investigate the impact of Sc doping on SrCoO x -based FET sensors, focusing on their response in highly alkaline solutions. Characterization techniques such as XRD, XPS, and cyclic voltammetry confirm the structural and electrochemical property changes in Sc-doped SrCoO x materials. The stability and selectivity of the 5 mol% Sc-doped sensor are demonstrated through repetitive testing in various NaOH concentrations, showcasing its potential for alkaline environment applications. The experimental results show a significant reduction in sensor response time, with an optimal doping level of 5 mol% Sc reducing the time to approximately 60 seconds. This enhancement is linked to the improved oxygen ion mobility within the cubic perovskite structure induced by Sc doping. DFT calculations substantiate the experimental findings, revealing the stabilization of the cubic phase and increased oxygen vacancy formation energy at Sc-O-Co sites, which aligns with the improved response dynamics. The calculations also provide insights into the electronic structure modifications due to Sc doping, contributing to sensor sensitivity and selectivity. This study offers a comprehensive understanding of Sc doping's effect on SrCoO x FET sensors, highlighting their potential for robust pH sensing in highly alkaline conditions. The findings pave the way for optimizing sensor materials through doping and computational design, setting a foundation for future research in electrochemical sensing technology. Sc doping significantly enhances the SrCoOx field-effect transistor (FET) sensor's response performance in highly alkaline solutions by improving oxygen ion mobility within the cubic perovskite structure.