Characterisation of rare earth selective emitters for thermophotovoltaic applications

We investigate selective radiation emitters made from rare earth oxides suitable for thermophotovoltaic (TPV) systems. Yb2O3 and Er2O3 emitters were fabricated and their radiation power, temperature and emissivity were measured in the entire relevant spectral range. We found temperatures of 1735 K for the Yb2O3 emitter and of 1680 K for the Er2O3 emitter both heated with a 1.35 kW butane burner. The maximum emissivities of the selective peaks were 0.85 at 1.27 eV, and 0.82 at 0.80 eV for the Yb2O3 and the Er2O3 emitter, respectively. The emission spectra show gas emission lines originating from the combustion process in addition to the selective emission bands. An estimation based on a simplified combustion model show that a TPV system with a system efficiency of about 10% can be realised using an Yb2O3 emitter, silicon photocells and a perfect selective filter.