Segregated tandem filter for enhanced conversion efficiency in a thermophotovoltaic energy conversion system

摘要

A filter system to transmit short wavelength radiation and reflect long wavelength radiation for a thermophotovoltaic energy conversion cell comprises an optically transparent substrate segregation layer with at least one coherent wavelength in optical thickness; a dielectric interference filter deposited on one side of the substrate segregation layer, the interference filter being disposed toward the source of radiation, the interference filter including a plurality of alternating layers of high and low optical index materials adapted to change from transmitting to reflecting at a nominal wavelength lambda IF approximately equal to the bandgap wavelength lambda g of the thermophotovoltaic cell, the interference filter being adapted to transmit incident radiation from about 0.5 lambda IF to lambda IF and reflect from lambda IF to about 2 lambda IF; and a high mobility plasma filter deposited on the opposite side of the substrate segregation layer, the plasma filter being adapted to start to become reflecting at a wavelength of about 1.5 lambda IF.