Spectral selectivity from resonant-coupling in microgap-TPV

Near-field energy coupling between two surfaces may arise from frustrated total-internal-reflectance and from atomic dipole-dipole interaction. Such an exchange of energy, if at resonance, greatly enhances the radiation transfer between an emitter and a photovoltaic converter. Computational modeling of selected, but realizable, emitter and detector structures and materials shows the benefits of both near-field and resonance coupling (e.g., with ~ 100nm gaps). In one sense, this is almost an engineering paper. A strong computational model (based on physically-proven concepts and incorporating known and predicted high-temperature properties of acceptable emitter materials) is used to demonstrate the potential of materials (properly-selected to overcome natural limitations) and of structures (carefully crafted to push the limits of present technology) for breaking barriers of thermal conversion at lower-emitter temperatures (< 1000C).