Effect of aluminum on the thermoelectric properties of nanostructured PbTe

• Published in: Nanotechnology Vol. 24; no. 34; p. 345705
• Main Authors: Zhang, Qinyong, Yang, Siqi, Zhang, Qian, Chen, Shuo, Liu, Weishu, Wang, Hui, Tian, Zhiting, Broido, David, Chen, Gang, Ren, Zhifeng
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 30.08.2013; Institute of Physics
• Subjects: Aluminum; Aluminum - chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Conduction band; Cross-disciplinary physics: materials science; rheology; Diffusion; Electric Conductivity; Electricity; Electron states; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Electrons; Exact sciences and technology; Fermi surfaces; Intermetallics; Lead - chemistry; Lead base alloys; Lead tellurides; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Methods of electronic structure calculations; Methods of nanofabrication; Nanostructure; Nanostructures - chemistry; Nanostructures - ultrastructure; Physics; 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); Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Tellurium - chemistry; Temperature; Thermoelectricity; X-Ray Diffraction; Conduction bands; Density of states; Electrical conductivity; Doping; Seebeck effect; Nanostructures; Thermoelectric properties; Hot pressing; Electronic structure; Fermi level; Aluminium additions; Density functional method; Effective mass; Figure of merit; Nanomaterial synthesis
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/0957-4484/24/34/345705

In the present work, the effect of aluminum (Al) on the thermoelectric properties of PbTe is studied. Aluminum doped PbTe samples, fabricated by a ball milling and hot pressing, have Seebeck coefficients between −100 and −200 μV K−1 and electrical conductivities of (3.6-18) × 104 S m−1 at room temperature, which means that Al is an effective donor in PbTe. The first principle calculations clearly show an increase of the density of states close to the Fermi level in the conduction band due to Al doping, which averages up the energy and effective mass of electrons, resulting in enhancement of the Seebeck coefficient. The maximum figure-of-merit ZT of 1.2 is reached at 770 K in the Al0.03PbTe sample.