Enhancement of Bi2O2Se thermoelectric power factor via Nb doping

Bi2O2Se is a promising thermoelectric material, but in its pristine form, its low carrier concentrations (similar to 10(15) cm(-3)) induce low electrical conductivity and thermoelectric performance. To increase its electrical conductivity, substitution of Nb5+ ions for Bi3+ ions was carried out. Pure and Nb-doped Bi2O2Se were synthesized by solid-state reactions, and XRD analysis, XPS spectra, and FE-SEM were used to verify the synthesis of Bi2-xNbxO2Se. The electrical conductivity, sigma, and Seebeck coefficient, S, were used to quantify the thermoelectric performance. As the niobium content increased, the electrical conductivity enhanced, whereas the Seebeck coefficient declined. A maximum power factor value of 7 mu W cm(-1).K-2 at 473 K was achieved for Bi1.9Nb0.1O2Se, which is similar to 2.6 times that of pure Bi2O2Se at the same temperature. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Doping Bi2O2Se with Nb can increase its electrical conductivity but decrease the Seebeck coefficient. As the niobium content increases, the electrical conductivity increases, and the maximum power factor reaches the highest value.