Electronic Structure and Transport Properties of Doped Lead Chalcogenides from First Principles
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Electronic Structure and Transport Properties of Doped Lead Chalcogenides from First Principles Piotr Śpiewak and Krzysztof J. Kurzydłowski MRS Advances / FirstView Article / August 2016, pp 1 - 8 DOI: 10.1557/adv.2016.559, Published online: 14 August 2016
Link to this article: http://journals.cambridge.org/abstract_S2059852116005594 How to cite this article: Piotr Śpiewak and Krzysztof J. Kurzydłowski Electronic Structure and Transport Properties of Doped Lead Chalcogenides from First Principles. MRS Advances, Available on CJO 2016 doi:10.1557/adv.2016.559 Request Permissions : Click here
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MRS Advances © 2016 Materials Research Society DOI: 10.1557/adv.2016.559
Electronic Structure and Transport Properties of Doped Lead Chalcogenides from First Principles Piotr Śpiewak1 and Krzysztof J. Kurzydłowski1 1 Materials Design Division, Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507 Warsaw, Poland ABSTRACT The structural and electronic properties of lead chalcogenides PbX (X=S, Se, and Te) are investigated by first-principles calculations based on the range-separated hybrid functionals and semilocal generalized gradient approximation. It is found that an accurate band structure description requires the hybrid functional with the spin-orbit coupling included. Using this approach, the band structure of lead telluride and doped lead selenide are calculated, and its influences on the transport properties are discussed.
INTRODUCTION The direct energy conversion between heat and electricity based on thermoelectric effects (TE) is provided by a class of materials known as thermoelectric materials (TM). The conversion efficiency of TM is determined by the dimensionless figure of merit, defined as ZT = σS2T/(κel+κph), where σ is the electrical conductivity, S the Seebeck coefficient, T the absolute temperature, κel and κph are the electronic and phonon thermal conductivity, respectively. Consequently, the concept of improving TM performance require minimal thermal transport (κ=κel+κph in the denominator) and high electrical conductivity with a large Seebeck coefficient. Recent progress in TM [1-3 and references therein] has primarily been made by lowering κph by introducing phonon scattering centers such as mass contrast [4] and nanostructure [5] in bulk materials. The other attempt to improve of ZT is to optimize the electronic terms, σS2 known as power factor (PF), by the band structure engineering strategies [6]. Since the lattice thermal conductivity of the thermoelectric materials has already been greatly reduced [7], for further enhancement of ZT it is most important to control the band structure near the Fermi level (EF) via a chemical doping [8-11]. Modelling and simulation have an important role in the development of materials for thermoelectric energy co
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