Reduction of the thermal conductivity in free-standing silicon nano-membranes investigated by non-invasive Raman thermometry
Research output: Contribution to journal › Article › Scientific › peer-review
We report on the reduction of the thermal conductivity in ultra-thin suspended Si membranes with high crystalline quality. A series of membranes with thicknesses ranging from 9 nm to 1.5 ìm was investigated using Raman thermometry, a novel contactless technique for thermal conductivity determination. A systematic decrease in the thermal conductivitywas observed as reducing the thickness, which is explained using the Fuchs-Sondheimer model through the influence of phonon boundary scattering at the surfaces. The thermal conductivity of the thinnest membrane with d = 9 nm resulted in (9 ± 2) W/mK, thus approaching the amorphous limit but still maintaining a high crystalline quality.
Chavez-Angel, E., Reparaz, J. S., Gomis-Bresco, J., Wagner, M. R., Cuffe, J., Graczykowski, B., Shchepetov, A., Jiang, H., Prunnila, M., Ahopelto, J., Alzina, F., & Sotomayor Torres, C. M. (2014). Reduction of the thermal conductivity in free-standing silicon nano-membranes investigated by non-invasive Raman thermometry. APL Materials, 2(1). https://doi.org/10.1063/1.4861796