The thermal conductivities of nonporous and nanoporous Bi thin films. (a) The thermal conductivities of nanoporous Bi thin films as a function of pore diameters. (b) The average thermal conductivities of nonporous and nanoporous Bi thin films plotted against their neck size at room temperature and compared to those of a Bi NW (approximately 123 nm in diameter) at 280 K. Insets show SEM images, and table provides a summary of the geometric parameters of the Bi thin films, n is the neck size, p is the pitch size, and d is pore size, as indicated in the inset. The scale bar is 500 nm.
Kim et al. Nanoscale Research Letters 2013 8:371 doi:10.1186/1556-276X-8-371