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 μm 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.