Effects of Doping on Transport Properties in Cu-Bi-Se-Based Thermoelectric Materials

作者：Hwang Jae Yeol; Mun Hyeon A; Kim Sang Il; Lee Ki Moon; Kim Jungeun; Lee Kyu Hyoung^*; Kim Sung Wng

来源：Inorganic Chemistry, 2014, 53(24): 12732-12738.

DOI：10.1021/ic5014945

The thermoelectric properties of Zn-, In-, and I-doped Cu1.7Bi4.Se-7(8) pavonite homologues were investigated in the temperature range from 300 to 560 K. On the basis of the comprehensive structural analysis using Rietveld refinement of synchrotron radiation diffraction for Cux+yBi5-ySe8 compounds with the inherently disordered crystallographic sites, we demonstrate a doping strategy that provides a simultaneous control for enhanced electronic transport properties by the optimization of carrier concentration and exceptionally low lattice thermal conductivity by the formation of point defects. Substituted Zn or In ions on Cu site was found to be an effective phonon scattering center as well as an electron donor, while doping on Bi site showed a moderate effect for phonon scattering. In addition, we achieved largely enhanced power factor in small amount of In doping on Cu site by increased electrical conductivity and moderately decreased Seebeck coefficient. Coupled with a low lattice thermal conductivity originated from intensified point defect phonon scattering by substituted In ions with host Cu ions, a thermoelectric figure of merit ZT of 0.24 at 560 K for Cu1.6915In0.0085Bi4.7Se8 was achieved, yielding 30% enhancement compared with that of a pristine Cu1.7Bi4.7Se8 at the same temperature.

• 出版日期2014-12-15
• 单位RIKEN