• Shibata, Keisuke
• Kato, Shinya

Abstract

<jats:title>Abstract</jats:title><jats:p>Boron-doped silicon nanocrystals (Si-NCs)/amorphous silicon oxide (a-SiO<jats:italic><jats:sub>y</jats:sub></jats:italic>) multilayers were prepared by plasma-enhanced chemical vapor deposition and post-annealing of boron-doped Si-rich amorphous silicon oxide (a-SiO<jats:sub><jats:italic>x</jats:italic></jats:sub>) and a-SiO<jats:italic><jats:sub>y</jats:sub></jats:italic> multilayers. The diameter of Si-NCs was changed by varying the thickness of the a-SiO<jats:sub><jats:italic>x</jats:italic></jats:sub> layer (<jats:italic>t</jats:italic><jats:sub>a-SiO<jats:italic>x</jats:italic></jats:sub>) from 3 to 50 nm. The electrical conductivity (<jats:italic>σ</jats:italic>) was increased in the <jats:italic>t</jats:italic><jats:sub>a-SiO<jats:italic>x</jats:italic></jats:sub> range of 3 to 13 nm and saturated around 5.7 kS·m<jats:sup>−1</jats:sup>. This tendency corresponds to crystal volume fraction in the Si-NCs multilayers. Seebeck coefficient (<jats:italic>S</jats:italic>) was almost constant at 230 <jats:italic>μ</jats:italic>V·K<jats:sup>−1</jats:sup> and showed no dependence on <jats:italic>t</jats:italic><jats:sub>a-SiO<jats:italic>x</jats:italic></jats:sub>. Thermal conductivity (<jats:italic>κ</jats:italic>) was in the range of 1.4–1.5 W·m<jats:sup>−1</jats:sup>·K<jats:sup>−1</jats:sup> and almost independent of <jats:italic>t</jats:italic><jats:sub>a-SiO<jats:italic>x</jats:italic></jats:sub>, which is much lower than that of bulk Si. A maximum power factor of 0.33 mW·m<jats:sup>−1</jats:sup>·K<jats:sup>−2</jats:sup> was obtained at <jats:italic>t</jats:italic><jats:sub>a-SiO<jats:italic>x</jats:italic></jats:sub> = 13 nm.</jats:p>

Topics

• impedance spectroscopy
• amorphous
• Silicon
• Boron
• annealing
• thermal conductivity
• electrical conductivity
• chemical vapor deposition