Abstract
Reducing thermal conductivity while avoiding adverse interfacial reactions during sintering is crucial for improving the thermoelectric performance of Bi2Te3-based composites.Inert ceramic nanoparticles are good candi-dates for achieving this goal.In this study,we designed and prepared a series of p-type Bi0.5Sb1.5Te3 nanocomposites decorated with Y2O3 ceramic nanoparticles via ball-milling dispersion and spark-plasma sintering.Owing to the chemical stability of the ceramics,no traces of atomic doping or interfacial reactions were observed.Transport measurements revealed that the Y2O3 nanoparticles dis-tributed along the grain boundaries acted as energy-de-pendent carrier-filtering centers to improve the scattering parameter and Seebeck coefficient,contributing to the elevated power factor even with a decreased electrical conductivity.Moreover,the incorporated Y2O3 nanoparti-cles and various defect structures they induced effectively strengthened the phonon scattering and suppressed the lattice thermal conductivity.Consequently,a peak figure of merit(ZT)of 1.23 at 313 K was achieved for 0.4％Y2O3/Bi0.5Sb1.5Te3,which is 13％higher than that of the matrix.In addition,the Vickers hardness of the composite material was 35％higher than that of the matrix.This study demonstrates the effectiveness of ceramic nanoparticles in synergistically improving the thermoelectric and mechan-ical properties,which may be further extended to other thermoelectric systems.
基金项目
National Natural Science Foundation of China(11834012)
National Natural Science Foundation of China(52130203)
NETL
NSTL
万方数据