Simulation of Surface Sensing Behavior of Pt Doped SnO2 (110) with CO
The IUP Journal of Electrical & Electronics Engineering, Vol. XI, No. 2, April 2018, pp. 41-52
Posted: 4 Nov 2018
Date Written: October 13, 2018
To study the sensing mechanism at atomic, geometrical and electronic structural levels, Density Functional Theory (DFT) technique is useful. Based on ab initio, DFT calculations for CO gas sensing behavior on undoped and Pt doped SnO2 are done. After surface relaxation, optimum adsorption site is selected based on adsorption energy calculated for four different sites, O2C (bridging oxygen), Sn6c (6 fold Sn), Sn5c (5 fold Sn) and O3c (plane oxygen), and CO sensing behavior is observed on favorable site. For estimation of conductance, which is a measure of sensitivity of gas sensing system, analysis of related physical parameters like surface Density Of States (DOS) and Mulliken population analysis are done. Enhanced sensitivity is observed for Pt doped surface as compared to undoped ones, which is in agreement with the experimental results. Modeling and simulations help to optimize the sensor for any specific application, prior to fabrication. Conclusions help in designing the framework of SnO2-based CO gas sensor.
Keywords: SnO2, Density Functional Theory (DFT), CO gas sensing, Density Of States (DOS), Platinum, Doping, Adsorption energy, CASTEP
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