Enhancement in thermoelectric properties due to Ag nanoparticles incorporated in Bi2Te3 matrix

Beilstein Journal of Nanotechnology

Ajay Dhar^3¹  Srashti Gupta^1²  Dinesh Chandra Agarwal^2³  Kandasami Asokan^5⁴  Sankarakumar Amrithpandian^4⁵  Bathula Sivaiah^3⁶ 

[1] Amity Institute of Nanotechnology, Amity University, Noida-Uttar Pradesh-201303, India more less^6;Department of Physics and Astrophysics, University of Delhi, New Delhi-110007, India^1;Department of Physics, Sant Longowal Institute of Engg and Tech. Longowal, Punjab-148106, India^2;Material Science, Inter University Accelerator Centre, New Delhi, Delhi 110067, India^5;Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, India^4;Physics of Energy Harvesting Division, CSIR - National Physical Laboratory, Delhi-110007, India^3

关键词: bismuth telluride;    nanoparticles;    power factor;    thermoelectric power;   

DOI  :  10.3762/bjnano.10.63

学科分类：地球科学(综合)

来源: Beilstein - Institut zur Foerderung der Chemischen Wissenschaften

【 摘 要 】

The present study aims to see the enhancement in thermoelectric properties of bismuth telluride (Bi₂Te₃) annealed at different temperatures (573 and 773 K) through silver (Ag) nano-inclusions (0, 2, 5, 10, 15 and 20 wt %). Transmission electron microscopy (TEM) images of Ag incorporated in Bi₂Te₃ annealed at 573 K shows tubular, pentagonal, trigonal, circular and hexagonal nanoparticles with sizes of 6–25 nm (for 5 wt % Ag ) and 7–30 nm (for 20 wt % Ag). Ag incorporated in Bi₂Te₃ annealed at 773 K shows mainly hexagonally shaped structures with particle sizes of 2–20 nm and 40–80 nm (for 5 wt % Ag) and 10–60 nm (for 20 wt % Ag). Interestingly, the samples annealed at 573 K show the highest Seebeck coefficient (S, also called thermopower) at room temperature (p-type behavior) for 5% Ag which is increased ca. five-fold in comparison to Ag-free Bi₂Te₃, whereas for samples with the same content (5% Ag) annealed at 773 K the increment in thermopower is only about three-fold with a 6.9-fold enhancement of the power factor (S²σ). The effect of size and shape of the nanoparticles on thermoelectric properties can be understood on the basis of a carrier-filtering effect that results in an increase in thermopower along with a control over the reduction in electrical conductivity to maintain a high power factor yielding a high figure of merit.

【 授权许可】

CC BY