Chirumamilla, ManoharManoharChirumamillaKrishnamurthy, Gnanavel VaidhyanathanGnanavel VaidhyanathanKrishnamurthyKnopp, KatrinKatrinKnoppKrekeler, TobiasTobiasKrekelerGraf, MatthiasMatthiasGrafJalas, DirkDirkJalasRitter, MartinMartinRitterStörmer, MichaelMichaelStörmerPetrov, AlexanderAlexanderPetrovEich, ManfredManfredEich2019-06-132019-06-132019-05-10Scientific Reports (9): 7241 (2019-05-10)http://hdl.handle.net/11420/2734High temperature stable selective emitters can significantly increase efficiency and radiative power in thermophotovoltaic (TPV) systems. However, optical properties of structured emitters reported so far degrade at temperatures approaching 1200 °C due to various degradation mechanisms. We have realized a 1D structured emitter based on a sputtered W-HfO 2 layered metamaterial and demonstrated desired band edge spectral properties at 1400 °C. To the best of our knowledge the temperature of 1400 °C is the highest reported for a structured emitter, so far. The spatial confinement and absence of edges stabilizes the W-HfO 2 multilayer system to temperatures unprecedented for other nanoscaled W-structures. Only when this confinement is broken W starts to show the well-known self-diffusion behavior transforming to spherical shaped W-islands. We further show that the oxidation of W by atmospheric oxygen could be prevented by reducing the vacuum pressure below 10 −5 mbar. When oxidation is mitigated we observe that the 20 nm spatially confined W films survive temperatures up to 1400 °C. The demonstrated thermal stability is limited by grain growth in HfO 2 , which leads to a rupture of the W-layers, thus, to a degradation of the multilayer system at 1450 °C.en2045-232220197241https://creativecommons.org/licenses/by/4.0/spectral propertiesself-diffusionPhysikJournal Articleurn:nbn:de:gbv:830-882.03566810.15480/882.227510.1038/s41598-019-43640-610.15480/882.2275Other