Work

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

Year: 2016

Type: article

Abstract: 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.

Source: Applied Physics Letters

DOI: 10.1063/1.4960197

Authors: Claudia Mangold, Sanghamitra Neogi, Davide Donadio

Institutions: University of Colorado Boulder, Max Planck Institute for Polymer Research, University of California, Davis

Language: English

Topic: Advanced Thermoelectric Materials and Devices

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funder: European Commission

Award: Membrane-based phononic engineering for energy harvesting