Near-Field Radiative Transfer Between Heavily Doped SiGe at Elevated Temperatures

SiGe alloys represent an important type of high-temperature semiconductor material for solid-state energy conversion. In the present study, the near-field radiative heat transfer between heavily doped SiGe plates is investigated. A dielectric function model is formulated based on the previously reported room-temperature mobility and temperature-dependent electric resistivity of several silicon-rich alloys with different doping type and concentration. The fluctuational electrodynamics is used to evaluate the near-field noncontact heat transfer coefficient. The variation of the heat transfer coefficient with doping concentration and temperature is explained according to the change in the optical constants and in the spectral distribution of the near-field heat flux.