High-performance selective Er-doped YAG emitters for thermophotovoltaics

Selective emitters for thermophotovoltaics have been produced by vacuum plasma-spray coating of erbium doped garnet Er1.5Y1.5Al5O12 and Er2O3 on the intermetallic alloy MoSi2. The emitters are fully operable in an oxygen-containing atmosphere at a temperature of 1600 °C, are highly thermal-shock stable, and show good selective-emitting properties. The film thickness of the rare-earth oxide was varied between 200 and 600 [mu]m and an optimal thickness for maximum selectivity was found. Measurements with Si and GaSb photocells have been performed in order to evaluate the optimal combination emitter - photocell for real thermophotovoltaic systems.