Optimal thickness of silicon membranes to achieve maximum thermoelectric efficiency: A first principles study

Journal Article · Mon Aug 01 00:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4960197· OSTI ID:22594405

Mangold, Claudia ^[1]; Neogi, Sanghamitra ^[2]; Donadio, Davide ^[3]

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1. Max Planck Institut für Polymerforschung, Ackermannweg 10, D-55128 Mainz (Germany)
2. Department of Aerospace Engineering Sciences, University of Colorado Boulder, Boulder, Colorado 80309 (United States)
3. Department of Chemistry, University of California Davis, One Shields Ave., Davis, California 95616 (United States)

Silicon nanostructures with reduced dimensionality, such as nanowires, membranes, and thin films, are promising thermoelectric materials, as they exhibit considerably reduced thermal conductivity. Here, we utilize density functional theory and Boltzmann transport equation to compute the electronic properties of ultra-thin crystalline silicon membranes with thickness between 1 and 12 nm. We predict that an optimal thickness of ∼7 nm maximizes the thermoelectric figure of merit of membranes with native oxide surface layers. Further thinning of the membranes, although attainable in experiments, reduces the electrical conductivity and worsens the thermoelectric efficiency.

• OSTI ID: 22594405
• Journal Information: Applied Physics Letters, Vol. 109, Issue 5; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BOLTZMANN EQUATION
DENSITY FUNCTIONAL METHOD
EFFICIENCY
ELECTRIC CONDUCTIVITY
LAYERS
MEMBRANES
NANOWIRES
OXIDES
SILICON
THERMAL CONDUCTIVITY
THERMOELECTRIC MATERIALS
THICKNESS
THIN FILMS