Enhancement in Thermoelectric Power in Lead Telluride Nanocomposite: Role of Oxygen Vis-À-Vis Nanostruct

Author(s) B. Paul, P. Banerji
Affiliations Materials Science Centre Indian Institute of Technology, Kharagpur 721302, India
Е-mail biplabpaul2006@yahoo.co.in
Issue Volume 3, Year 2011, Number 1, Part 4
Dates Received 04 February 2011, in final form 13 October 2011, published online 17 October 2011
Citation B. Paul, P. Banerji, J. Nano- Electron. Phys. 3 No1, 691 (2011)
PACS Number(s) 62.23.Pq, 71.20.Nr, 73.50.Lw
Key words Lead telluride, Hot-press, Nanocomposite (23) , Thermoelectric (7) , Energy filtering.
The present work reports enhanced power factor and reduced value of room temperature thermal conductivity in undoped PbTe nanocomposite, prepared from PbTe nanocrystals, synthesized via chemical route. The highest power factor is found to be 19.21 x 10 –4 Wm –1K –2 with room temperature thermal conductivity of 1.53 Wm –1K –1. The potential barrier at the sharp interfaces of the grains of the nanocomposites, occurred due to the adsorption of oxygen by the grain surfaces, have been found to play the main role to produce the high value of Seebeck coefficient (416 μV/K at 500 K) by preferentially scattering the lower energy electrons and thus enhancing the power factor. The lattice destruction at the grain interfaces has been found to cause the remarkable reduction in thermal conductivity, through scattering a wide spectrum of phonon wavelength.