Effects of nitrogen doping and oxygen vacancies on thermoelectric properties of Pt/N-doped ITO thin film thermocouples: first-principles calculations and experiments

摘要

Abstract In this paper, the effects of nitrogen doping and oxygen vacancies on thermoelectric properties of Pt/N-doped ITO thin film thermocouples were discussed in detail from the perspective of thermodynamics and kinetics based on first-principles and experiments. The atomic structure and bonding characteristics of ITO and N-doped ITO were investigated by X-ray diffraction and X-ray photoelectron spectroscopy. The calculation results show that nitrogen doping makes the charge transfer to the Sn-N bond and produces anti-bonding states to the nearest neighbor Sn–O bond, so that the repair of oxygen vacancies in N-doped ITO requires a higher activation energy than ITO. The effects of band structure, carrier concentration and carrier effective mass on the Seebeck coefficients of ITO and N-doped ITO were further discussed in detail. Finally, Pt/ITO and Pt/N-doped ITO thin film thermocouples were fabricated on the Al2O3 substrates by magnetron sputtering to verify their thermoelectric stability. The calibration results also proved that N-doped ITO has higher thermoelectric stability than ITO. Graphical Abstract