Solid solutions of CdSe and CdTe in PbTe and their optical properties

Nikolić, P.M.

doi:10.1088/0508-3443/17/3/306

Cited by 34 publications

(29 citation statements)

References 5 publications

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“…Many experimental works were performed with alloying to adjust the convergence temperature to desired range. The band structure modifications of PbTe-based materials through isovalent substitutions by Mn, 58,59 IIB, 60 and IIA elements 61 were originally studied before 1980s, [62][63][64] and have been revisited with intensive investigation for TE applications. Compared to lead chalcogenides, the strategy of valley convergence through alloying plays a more important role in the zT enhancement for SnTe, since the room temperature energy offset between L and Σ valleys for SnTe is much higher (~0.3 eV for SnTe,~0.1 eV for PbTe).…”

Section: Valley Degeneracymentioning

confidence: 99%

Valleytronics in thermoelectric materials

et al. 2018

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The central theme of valleytronics lies in the manipulation of valley degree of freedom for certain materials to fulfill specific application needs. While thermoelectric (TE) materials rely on carriers as working medium to absorb heat and generate power, their performance is intrinsically constrained by the energy valleys to which the carriers reside. Therefore, valleytronics can be extended to the TE field to include strategies for enhancing TE performance by engineering band structures. This review focuses on the recent progress in TE materials from the perspective of valleytronics, which includes three valley parameters (valley degeneracy, valley distortion, and valley anisotropy) and their influencing factors. The underlying physical mechanisms are discussed and related strategies that enable effective tuning of valley structures for better TE performance are presented and highlighted. It is shown that valleytronics could be a powerful tool in searching for promising TE materials, understanding complex mechanisms of carrier transport, and optimizing TE performance.npj Quantum Materials (2018) 3:9 ; doi:10.1038/s41535-018-0083-6 INTRODUCTIONThe demand for renewable energy harvesting has been growing because of the limited fossil fuels and increasing worldwide energy consumption. Thermoelectric (TE) materials, which have the capability of converting heat directly into electricity under a temperature gradient, have been regarded as an alternative option to alleviate energy shortage.1 Though TE devices have already been applied in deep space exploration and solid state cooling, 2,3 the relatively low energy conversion efficiency limits their wide commercialization, 4 which is mainly constrained by the performance of TE materials as characterized by the dimensionless figure of merit, zT = α 2 σT/(κ e + κ L ), where α is the Seebeck coefficient, σ is the electrical conductivity, κ e and κ L are, respectively, the electronic and lattice contributions to the total thermal conductivity κ, and T is the absolute temperature.5 Since all three physical properties (α, σ, and κ) are carrier concentration dependent, zT could reach its maximum value at an optimized carrier concentration. zT max is determined by a combination of intrinsic physical parameters as well as the temperature, all of which integrated into a term called the TE quality factor, B. Higher quality factor B leads to higher zT max at a fixed temperature. With a single parabolic band model in the nondegenerate limit, B could be expressed as:

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Section: Valley Degeneracymentioning

confidence: 99%

Valleytronics in thermoelectric materials

et al. 2018

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“…5 An important characteristic of the PbTe-based ternary alloys is that their band gap is very sensitive not only to temperature, like in PbTe, but also to composition. It has been shown that the energy gap of PbTe increases monotonically when alloyed with Cd 6,7 as well as with Mn. 8 Due to big, ca 1 eV, difference between the energy gaps of PbTe and CdTe, PbTe-CdTe system appears especially suitable for band-gap engineering with a potential for a variety of photonic, thermoelectric and photovoltaic applications.…”

Section: Introductionmentioning

confidence: 99%

“…6,7,16 Recently, high quality single Pb 1−x Cd x Te crystals with x as high as 0.11 were obtained 17 by self-selecting vapor growth method.…”

Section: Introductionmentioning

confidence: 99%

Structural and electronic properties of Pb1−xCdxTe and Pb1
Bukała
¹
,
Sankowski
²
,
Buczko
³

et al. 2012
Phys. Rev. B
24
5
6
0
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A systematic theoretical study of two PbTe-based ternary alloys, Pb1−xCdxTe and Pb1−xMnxTe, is reported. First, using ab initio methods we study the stability of the crystal structure of CdTePbTe solid solutions, to predict the composition for which rock-salt structure of PbTe changes into zinc-blende structure of CdTe. The dependence of the lattice parameter on Cd (Mn) content x in the mixed crystals is studied by the same methods. The obtained decrease of the lattice constant with x agrees with what is observed in both alloys. The band structures of PbTe-based ternary compounds are calculated within a tight-binding approach. To describe correctly the constituent materials new tight-binding parameterizations for PbTe and MnTe bulk crystals as well as a tight-binding description of rock-salt CdTe are proposed. For both studied ternary alloys, the calculated band gap in the L point increases with x, in qualitative agreement with photoluminescence measurements in the infrared. The results show also that in p-type Pb1−xCdxTe and Pb1−xMnxTe mixed crystals an enhancement of thermoelectrical power can be expected.

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“…Due to the same reasons, the growth of uniform Pb 1−x Cd x Te bulk crystals with high Cd content, which would be important for certain, e.g., thermoelectric, applications is very difficult. So far, only polycrystalline Pb 1−x Cd x Te bulk samples were obtained by rapid quenching and annealing method [2][3][4] or by the Bridgman technique [5]. For Pb 1−x Cd x Te quenched alloys, the change of the lattice parameter and energy gap with x as well as the solubility limit have been studied by Rosenberg et al [2], Nikolic [3] and Leute and Schmidt [4].…”

Section: Introductionmentioning

confidence: 99%

Experimental and Theoretical Analysis οf PbTe-CdTe Solid Solution Grown by Physical Vapour Transport Method

et al. 2009

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Solid solutions of CdSe and CdTe in PbTe and their optical properties

Cited by 34 publications

References 5 publications

Valleytronics in thermoelectric materials

Valleytronics in thermoelectric materials

Structural and electronic properties of Pb1−xCdxTe and Pb1
Bukała
¹
,
Sankowski
²
,
Buczko
³

et al. 2012
Phys. Rev. B
24
5
6
0
View full text Add to dashboard Cite

Experimental and Theoretical Analysis οf PbTe-CdTe Solid Solution Grown by Physical Vapour Transport Method

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Solid solutions of CdSe and CdTe in PbTe and their optical properties

Cited by 34 publications

References 5 publications

Valleytronics in thermoelectric materials

Valleytronics in thermoelectric materials

Structural and electronic properties of Pb1−xCdxTe and Pb1Bukała1, Sankowski2, Buczko3 et al. 2012Phys. Rev. B24560View full textAdd to dashboardCite

Experimental and Theoretical Analysis οf PbTe-CdTe Solid Solution Grown by Physical Vapour Transport Method

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Product

Resources

About

Structural and electronic properties of Pb1−xCdxTe and Pb1
Bukała
¹
,
Sankowski
²
,
Buczko
³

et al. 2012
Phys. Rev. B
24
5
6
0
View full text Add to dashboard Cite