Prototype of radioisotope thermophotovoltaic system using photonic crystal spectral control

Abstract

This work describes a prototype of a small-size radioisotope thermophotovoltaic (RTPV) system with the two-dimensional metallic photonic crystal emitter and the low bandgap TPV cell. The project demonstrates the simulation and measurement of a system powered by an electrical heat source that mimics the radioisotope fuel pellet. The photonic crystal and the polished Ta3%W substrate are both used as the emitting surfaces to demonstrate the benefits of spectral control. The rest of the system is thermally insulated to increase the overall system efficiency. The photonic crystal emitter demonstrates four times more output power over a flat metal emitter from the 1 cm[superscript 2] TPV cell. With more cell areas, better TPV cells and improved insulation design, the system is expected to reach an efficiency of 7.8%.