Figure 6
From: Metamaterial emitter for thermophotovoltaics stable up to 1400 °C
Morphology and degradation of the layered metamaterial emitter due to grain growth in the HfO2 at an annealing temperature of 1400 °C and 1450 °C at a high vacuum condition of 3 × 10−5 mbar. STEM image (a–c) and element mapping (d–l, spectrum imaging for W, Hf and O) of the emitter structure, for as fabricated and annealed for 6 h at 1400 and 1450 °C.
