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 &lgr;.sub. IF approximately equal to the bandgap wavelength &lgr;.sub.g of the thermophotovoltaic cell, the interference filter being adapted to transmit incident radiation from about 0.5&lgr;.sub.IF to &lgr;.sub. IF and reflect from &lgr;.sub.IF to about 2&lgr;.sub.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&lgr;.sub.IF.