Measurement of the Kapitza resistance across a bicrystal interface

The Kapitza resistance across a Si bicrystal interface was measured using a pump probe optical technique. This approach, termed time resolved thermal wave microscopy (TRTWM), uses ultrafast laser pulses to image lateral thermal transport in bare semiconductors. The sample geometry is that of a Si bicrystal with the vertically oriented boundary intersecting the sample surface. High resolution transmission electron microscopy of the boundary region revealed a thin SiO2 layer at the interface. By comparing experimental results with a continuum thermal transport model the Kapitza resistance between the Si and SiO2 was estimated to be 2.3 × 10−9 m2K/W.