HIGH CONTRAST FAR-FIELD RADIATIVE THERMAL DIODE

摘要

A far-field radiative thermal rectification device uses a phase change material to achieve a high degree of asymmetry in radiative heat transfer. The device has a multilayer structure on one side and a blackbody on other side. The multilayer structure can consist of a transparent thin film of KBr sandwiched between a thin film of VO₂ and a reflecting layer of gold. When VO₂ is in its insulating phase, the structure is highly reflective due to the two transparent layers on highly reflective gold. When VO₂ is in the metallic phase, Fabry-Perot type of resonance occurs and the tri-layer structure acts like a wide-angle antireflection coating achieved by destructive interference of partially reflected waves making it highly absorptive for majority of spectral range of thermal radiation. The instant structure can form the active part of a configuration that acts like a far-field radiative thermal diode.