Thermal properties of carbon inverse opal photonic crystals

The thermal conductivity of thin-wall glassy carbon and graphitic carbon inverse opals, fabricated by templating of silica opal has been measured in the temperature range 10-400 K using transient pulse method. The heat flow through 100 Å-thick layers of graphite sheets tiled on spherical surfaces of empty overlapping spheres arrayed in face-centered-cubic lattices has been analyzed in term of anisotropy factor. Taking into account high anisotropy factor in graphite, γ=342, we found that the thermal conductivity of inverse opal prepared by chemical vapor deposition infiltration is limited by heat flow across the graphitic layers in bottleneck, κ⊥=3.95 W/m K. The electronic contribution to the thermal conductivity, κe(300 K)=3.7×10−3 W/m K is negligible comparing to the measured value, κ(300 K)=0.33 W/m K. The obtained phonon mean free path, l=90 nm is comparable with the graphite segments between hexagonal array of interconnections.