| Popis: |
Semiconductor nanowires hold great promise for applications such as nano-electronics and energy conversion. A detailed knowledge of the thermal properties of the nanowire materials is essential for proper thermal management in nano-devices and thermal energy conversion. Prior thermal measurements on individual nanowires have shown that nanowires have reduced lattice thermal conductivity and, in some cases, enhanced thermoelectric properties. However, such thermal measurements are limited to nanowire thermal conductance of the order of 1 nW/K and are typically limited to nanowire diameters greater than 20 nm. Measurements to obtain the thermal conductivities of single nanowires with smaller diameter nanowires, which may exhibit even lower thermal conductivity and possibly quantum confinement effect at low temperature, have proven elusive. Herein, we demonstrated an experimental technique with improved measurement sensitivity that is capable of measuring the thermal conductance of 10 pW/K. This more sensitive technique overcomes several issues with current instrumentations and provides a tool for characterizing the properties of much smaller diameter nanowires, such as nanowires with 1 W/m-K thermal conductivity, 10 nm diameter and 1 μm length. Measurement enabled by this measurement platform will improve our understanding of thermal transport in confined nanostructures.Copyright © 2011 by ASME |
