Steady-State Measurements of Near-Field Radiative Heat Transfer between Ultra-Flat Thin-Film Materials

The total radiative heat transfer between two objects is limited by Planck’s radiation law. However, when the gap spacing between the two objects becomes smaller than the characteristic thermal wavelength, it is possible to greatly surpass this limit. The research objective is to prove this enhancement by using a steady-state apparatus to measure the radiative heat flux between two ultra-flat SiO₂ plates separated by a 200nm nanosized gap. Harnessing this energy increase allows for applications directly related to thermophotovoltaic energy conversion, contactless thermal rectification, and radiative cooling.