Thermoelectric Property Studies on Cu-Doped n-type CuxBi2Te2.7Se0.3 Nanocomposites

Combining high energy ball‐milling and hot‐pressing, significant enhancements of the thermoelectric figure‐of‐merit (ZT) have been reported for p‐type Bi0.4Sb1.6Te3 nanocomposites. However, applying the same technique to n‐type Bi2Te2.7Se0.3 showed no improvement on ZT values, due to the anisotropic...

Full description

Saved in:
Bibliographic Details
Published in:Advanced energy materials 2011-07, Vol.1 (4), p.577-587
Main Authors: Liu, Wei-Shu, Zhang, Qinyong, Lan, Yucheng, Chen, Shuo, Yan, Xiao, Zhang, Qian, Wang, Hui, Wang, Dezhi, Chen, Gang, Ren, Zhifeng
Format: Article
Language:English
Subjects:
bismuth telluride
copper
Nanocomposites
Semiconductors
solar (photovoltaic), solar (thermal), solid state lighting, phonons, thermal conductivity, thermoelectric, defects, mechanical behavior, charge transport, spin dynamics, materials and chemistry by design, optics, synthesis (novel materials), synthesis (self-assembly), synthesis (scalable processing)
thermoelectrics
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Combining high energy ball‐milling and hot‐pressing, significant enhancements of the thermoelectric figure‐of‐merit (ZT) have been reported for p‐type Bi0.4Sb1.6Te3 nanocomposites. However, applying the same technique to n‐type Bi2Te2.7Se0.3 showed no improvement on ZT values, due to the anisotropic nature of the thermoelectric properties of n‐type Bi2Te2.7Se0.3. Even though texturing was effective in improving peak ZT of Bi2Te2.7Se0.3 from 0.85 to 1.04, reproducibility from batch to batch remains unsatisfactory. Here, we show that good reproducibility can be achieved by introducing an optimal concentration of 0.01 copper (Cu) per Bi2Te2.7Se0.3 to make Cu0.01Bi2Te2.7Se0.3 samples. A peak ZT value of 0.99 was achieved in Cu0.01Bi2Te2.7Se0.3 samples without texturing. With texturing by re‐pressing, the peak ZT was increased to 1.06. Aging in air for over 5 months did not deteriorate but further improved the peak ZT to 1.10. The mechanism by which copper improves the reproducibility, enhances the carrier mobility, and reduces the lattice thermal conductivity is also discussed. Combining high energy ball milling and hot pressing, a significant enhancement on thermoelectric figure‐of‐merit (ZT) has been reported in p‐type Bi0.4Sb1.6Te3 nanocomposites, however the reproducibility from batch to batch is unsatisfactory. Improved reproducibility can be achieved by introducing a concentration of 0.01 Cu per Bi2Te2.7Se0.3 to give Cu0.01Bi2Te2.7Se0.3 samples. A peak ZT value of 0.99 is obtained in Cu0.01Bi2Te2.7Se0.3 samples without texturing. When textured by re‐pressing, the peak ZT can be increased to 1.06. Aging in air for over 5 months does not cause deterioration but further improved the peak ZT to 1.10.
ISSN:1614-6832
1614-6840
DOI:10.1002/aenm.201100149