Radioisotope Micropower System Using Thermophotovoltaic Energy Conversion.

Recent advances in thermophotovoltaic (TPV) energy conversion efficiency have increased interest in investigating the use of TPV in a wider spectrum of applications. This paper discusses a micropower system under development that utilizes a radioisotope heat source, microelectromechanical (MEM) thermal insulation, 3-D tungsten photonic crystal (PC) emitter, and thermophotovoltaic modules for the energy conversion. The 3-D tungsten photonic crystal (PC) emitter is a selective emitter that is designed to match the bandgap of the TPV module. Compared to bulk tungsten, the PC has increased emittance in the convertible wavelength range and decreased emittance in the nonconvertible wavelength range, which results in a greater than 10% improvement in conversion efficiency. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]