Effect of asymmetric concentration profile on thermal conductivity in Ge/SiGe superlattices

被引：12

作者：

Hahn, Konstanze R. ^{[1
]}

Cecchi, Stefano ^{[2
]}

Colombo, Luciano ^{[1
,3
,4
,5
]}

机构：

[1] Univ Cagliari, Cittadella Univ, Dept Phys, I-09042 Monserrato, CA, Italy

[2] Paul Drude Inst Festkorperelekt, Dept Epitaxy, Hausvogteipl 5-7, D-10117 Berlin, Germany

[3] Inst Ciencia Mat Barcelona ICMAB CSIC, Campus UAB, Barcelona 08193, Spain

[4] CSIC, Catalan Inst Nanosci & Nanotechnol ICN2, Campus UAB, Barcelona 08193, Spain

[5] Barcelona Inst Sci & Technol, Campus UAB, Barcelona 08193, Spain

来源：

APPLIED PHYSICS LETTERS | 2016年 / 108卷 / 20期

关键词：

INTERATOMIC POTENTIALS; SILICON; SIGE; GERMANIUM; SYSTEMS;

D O I：

10.1063/1.4949491

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

The effect of the chemical composition in Si/Ge-based superlattices on their thermal conductivity has been investigated using molecular dynamics simulations. Simulation cells of Ge/SiGe superlattices have been generated with different concentration profiles such that the Si concentration follows a step-like, a tooth-saw, a Gaussian, and a gamma-type function in direction of the heat flux. The steplike and tooth-saw profiles mimic ideally sharp interfaces, whereas Gaussian and gamma-type profiles are smooth functions imitating atomic diffusion at the interface as obtained experimentally. Symmetry effects have been investigated comparing the symmetric profiles of the step-like and the Gaussian function to the asymmetric profiles of the tooth-saw and the gamma-type function. At longer sample length and similar degree of interdiffusion, the thermal conductivity is found to be lower in asymmetric profiles. Furthermore, it is found that with smooth concentration profiles where atomic diffusion at the interface takes place the thermal conductivity is higher compared to systems with atomically sharp concentration profiles. Published by AIP Publishing.

引用

页数：5

共 32 条

[1] LATTICE THERMAL CONDUCTIVITY OF DISORDERED SEMICONDUCTOR ALLOYS AT HIGH TEMPERATURES [J].

ABELES, B .

PHYSICAL REVIEW, 1963, 131 (05) :1906-&

[2] Enhanced thermoelectric figure-of-merit in spark plasma sintered nanostructured n-type SiGe alloys [J].

Bathula, Sivaiah ;

Jayasimhadri, M. ;

Singh, Nidhi ;

Srivastava, A. K. ;

Pulikkotil, Jiji ;

Dhar, Ajay ;

Budhani, R. C. .

APPLIED PHYSICS LETTERS, 2012, 101 (21)

[3] Nanostructured Bulk Silicon as an Effective Thermoelectric Material [J].

Bux, Sabah K. ;

Blair, Richard G. ;

Gogna, Pawan K. ;

Lee, Hohyun ;

Chen, Gang ;

Dresselhaus, Mildred S. ;

Kaner, Richard B. ;

Fleurial, Jean-Pierre .

ADVANCED FUNCTIONAL MATERIALS, 2009, 19 (15) :2445-2452

[4] Evolution of thermal, structural, and optical properties of SiGe superlattices upon thermal treatment [J].

Chen, Peixuan ;

Etzelstorfer, Tanja ;

Hackl, Florian ;

Katcho, Nebil A. ;

Chang, Hung-Tai ;

Nausner, Lukas ;

Lee, Sheng-Wei ;

Fromherz, Thomas ;

Stangl, Julian ;

Schmidt, Oliver G. ;

Mingo, Natalio ;

Rastelli, Armando .

PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE, 2016, 213 (03) :533-540

[5] Role of Surface-Segregation-Driven Intermixing on the Thermal Transport through Planar Si/Ge Superlattices [J].

Chen, Peixuan ;

Katcho, N. A. ;

Feser, J. P. ;

Li, Wu ;

Glaser, M. ;

Schmidt, O. G. ;

Cahill, David G. ;

Mingo, N. ;

Rastelli, A. .

PHYSICAL REVIEW LETTERS, 2013, 111 (11)

[6] COMPARISON OF SEMIEMPIRICAL POTENTIAL FUNCTIONS FOR SILICON AND GERMANIUM [J].

COOK, SJ ;

CLANCY, P .

PHYSICAL REVIEW B, 1993, 47 (13) :7686-7699

[7] SixGe1-x alloy as efficient phonon barrier in Ge/Si superlattices for thermoelectric applications [J].

Dettori, Riccardo ;

Melis, Claudio ;

Colombo, Luciano .

EUROPEAN PHYSICAL JOURNAL B, 2015, 88 (01) :1-7

[8] New directions for low-dimensional thermoelectric materials [J].

Dresselhaus, Mildred S. ;

Chen, Gang ;

Tang, Ming Y. ;

Yang, Ronggui ;

Lee, Hohyun ;

Wang, Dezhi ;

Ren, Zhifeng ;

Fleurial, Jean-Pierre ;

Gogna, Pawan .

ADVANCED MATERIALS, 2007, 19 (08) :1043-1053

[9] Tailoring thermal conductivity by engineering compositional gradients in Si1-x Ge x superlattices [J].

Ferrando-Villalba, Pablo ;

Lopeandia, Aitor F. ;

Xavier Alvarez, Francesc ;

Paul, Biplab ;

de Tomas, Carla ;

Isabel Alonso, Maria ;

Garriga, Miquel ;

Goni, Alejandro R. ;

Santiso, Jose ;

Garcia, Gemma ;

Rodriguez-Viejo, Javier .

NANO RESEARCH, 2015, 8 (09) :2833-2841

[10] Role of Disorder and Anharmonicity in the Thermal Conductivity of Silicon-Germanium Alloys: A First-Principles Study [J].

Garg, Jivtesh ;

Bonini, Nicola ;

Kozinsky, Boris ;

Marzari, Nicola .

PHYSICAL REVIEW LETTERS, 2011, 106 (04)

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