Near-field thermal radiation between doped silicon plates at nanoscale gaps

Radiative heat transfer can be significantly enhanced via photon tunneling through a nanometer-scale gap to the point that it exceeds the blackbody limit. Here we report quantitative measurements of the near-field thermal radiation between doped-Si plates (width0.28em0ex=0.28em0ex4800.28em0exμm and length0.28em0ex=0.28em0ex1.340.28em0excm). A novel MEMS-based platform enables us to maintain doped-Si plates at nanoscale gap distances that cannot be achieved by other methods. The measured radiative heat transfer coefficient was found to be 2.91 times greater than the blackbody limit at a 400-nm vacuum gap.