Spontaneously assembling periodic composition-modulated InGaAsP structures

Vavilova, L. S.; Kapitonov, V. A.; Murashova, A. V.; Pikhtin, N. A.; Tarasov, I. S.; Ipatova, I. P.; Shchukin, V. A.; Берт, Н. А.; Ситникова, A. А.

doi:10.1134/1.1187827

Cited by 8 publications

(3 citation statements)

References 6 publications

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“…This spatial modulation can be exploited to create coherently embedded nanostructures of a given phase into a thermoelectric matrix and thus create nanostructured thermoelectrics on a large reaction scale. The spinodal decomposition phenomenon is well-known in various intermetallic and polymer blend systems, , but less is known about it in semiconductors and insulators. − …”

Section: Resultsmentioning

confidence: 99%

“…The spinodal decomposition phenomenon is well-known in various intermetallic 34 and polymer blend systems, 35,36 but less is known about it in semiconductors and insulators. [37][38][39][40] Outside of the spinodal decomposition region phase separation occurs via the nucleation and growth mechanism. The latter requires large composition fluctuations to decrease the free energy.…”

Section: Resultsmentioning

confidence: 99%

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Spinodal Decomposition and Nucleation and Growth as a Means to Bulk Nanostructured Thermoelectrics: Enhanced Performance in Pb_1-_xSn_xTe−PbS

et al. 2007

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The solid-state transformation phenomena of spinodal decomposition and nucleation and growth are presented as tools to create nanostructured thermoelectric materials with very low thermal conductivity and greatly enhanced figure of merit. The systems (PbTe)(1-x)(PbS)(x) and (Pb(0.95)Sn(0.05)Te)(1-x)(PbS)(x) are not solid solutions but phase separate into PbTe-rich and PbS-rich regions to produce coherent nanoscale heterogeneities that severely depress the lattice thermal conductivity. For x > approximately 0.03 the materials are ordered on three submicrometer length scales. Transmission electron microscopy reveals both spinodal decomposition and nucleation and growth phenomena the relative magnitude of which varies with x. We show that the (Pb(0.95)Sn(0.05)Te)(1-x)(PbS)(x) system, despite its nanostructured nature, maintains a high electron mobility (>100 cm(2)/V x s at 700 K). At x approximately 0.08 the material achieves a very low room-temperature lattice thermal conductivity of approximately 0.4 W/m x K. This value is only 28% of the PbTe lattice thermal conductivity at room temperature. The inhibition of heat flow in this system is caused by nanostructure-induced acoustic impedance mismatch between the PbTe-rich and PbS-rich regions. As a result the thermoelectric properties of (Pb(0.95)Sn(0.05)Te)(1-x)(PbS)(x) at x = 0.04, 0.08, and 0.16 were found to be superior to those of PbTe by almost a factor of 2. The relative importance of the two observed modes of nanostructuring, spinodal decomposition and nucleation and growth, in suppressing the thermal conductivity was assessed in this work, and we can conclude that the latter mode seems more effective in doing so. The promise of such a system for high efficiency is highlighted by a ZT approximately 1.50 at 642 K for x approximately 0.08.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Spinodal Decomposition and Nucleation and Growth as a Means to Bulk Nanostructured Thermoelectrics: Enhanced Performance in Pb_1-_xSn_xTe−PbS

et al. 2007

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“…We assume that nonisoelectronic substitution of cation sites is a reason for the formation of PbI 2 NCLs of different sizes in CdI 2 matrix during the growth of PbCdI 2 crystals using the Bridgman method [11]. Besides, in our opinion, such a behavior could also be caused by spinodal decomposition of these solid solutions [21][22][23][24]. Thus, these materials are strongly heterogeneous solids and have a very complex crystal structure.…”

Section: Methodsmentioning

confidence: 95%

Nature of Radiative Recombination Processes in Layered Heterogeneous PbCdI₂ Thick Films: Promising Scintillator Materials

Bukivskii

Gnatenko

Piryatinskiĭ

et al. 2018

Advances in Condensed Matter Physics

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For the first time, PbCdI2 alloys in the form of thick films were prepared on a glass substrate using the conventional one-step chemical deposition method. The studies of the structural properties of these films showed that they have a very complex crystal structure, where PbI2 microcrystallites of micron and submicron sizes, as well as small nanoclusters (NCLs), are randomly formed in the CdI2 crystal matrix. It was found that the films show intense photo- and cathodoluminescence at room temperature. The temperature dependence of PL spectra of thick PbCdI2 films was studied. The nature of various radiative recombination processes in PbCdI2 films was established and it was shown that their PL spectra at room temperature are equally determined both by surface states in small PbI2 NCLs and by intrinsic defects in microcrystallites. The obtained PbCdI2 thick films can be considered as novel promising semiconductor materials for the development of effective inexpensive scintillator detectors for biomedical and industrial applications.

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Energetics of misfit dislocation dipoles in anisotropic epitaxial films with nanoscale compositional modulation

Choi

Earmme

2006

International Journal of Solids and Structures

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The elastic strain and stress fields associated with nanoscale compositional modulation in an anisotropic epitaxial film on an anisotropic substrate are obtained by using Stroh formalism and the Eshelby-type inclusion method. The composition of the epitaxial film is considered to periodically fluctuate in a surface soft mode, with the amplitude of the composition modulation maximal near the growing surface and decreasing exponentially into the film. It has been experimentally observed that the composition modulation affects the formation of a new type of crystal defects, i.e., misfit dislocation dipoles, in III-V compound semiconductor materials. The formation energy of a misfit dislocation dipole under the elastic fields due to the composition modulation is calculated in this study. It is composed of the core and self energies of two dislocations, the interaction energy between two dislocations, and the interaction energies between the composition modulation and two dislocations. Numerical calculations are performed for a dislocation dipole in a lattice-matched Ga 0.5 In 0.5 P film on a GaAs substrate.

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Spontaneously assembling periodic composition-modulated InGaAsP structures

Cited by 8 publications

References 6 publications

Spinodal Decomposition and Nucleation and Growth as a Means to Bulk Nanostructured Thermoelectrics: Enhanced Performance in Pb_1-_xSn_xTe−PbS

Spinodal Decomposition and Nucleation and Growth as a Means to Bulk Nanostructured Thermoelectrics: Enhanced Performance in Pb_1-_xSn_xTe−PbS

Nature of Radiative Recombination Processes in Layered Heterogeneous PbCdI₂ Thick Films: Promising Scintillator Materials

Energetics of misfit dislocation dipoles in anisotropic epitaxial films with nanoscale compositional modulation

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Spontaneously assembling periodic composition-modulated InGaAsP structures

Cited by 8 publications

References 6 publications

Spinodal Decomposition and Nucleation and Growth as a Means to Bulk Nanostructured Thermoelectrics: Enhanced Performance in Pb1-xSnxTe−PbS

Spinodal Decomposition and Nucleation and Growth as a Means to Bulk Nanostructured Thermoelectrics: Enhanced Performance in Pb1-xSnxTe−PbS

Nature of Radiative Recombination Processes in Layered Heterogeneous PbCdI2 Thick Films: Promising Scintillator Materials

Energetics of misfit dislocation dipoles in anisotropic epitaxial films with nanoscale compositional modulation

Contact Info

Product

Resources

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Spinodal Decomposition and Nucleation and Growth as a Means to Bulk Nanostructured Thermoelectrics: Enhanced Performance in Pb_1-_xSn_xTe−PbS

Spinodal Decomposition and Nucleation and Growth as a Means to Bulk Nanostructured Thermoelectrics: Enhanced Performance in Pb_1-_xSn_xTe−PbS

Nature of Radiative Recombination Processes in Layered Heterogeneous PbCdI₂ Thick Films: Promising Scintillator Materials