Facile Deposition of YSZ-Inverse Photonic Glass Films

Abstract

An alternative all-colloidal and single-step deposition method of yttrium-stabilized zirconia (YSZ)-infiltrated polymeric photonic glass films is presented. Heterocoagulation of oppositely charged polystyrene (PS) microspheres and YSZ nanocrystals in aqueous dispersions created PS/YSZ core-shell spheres. These composite particles were deposited on glass substrates by a simple drop-coating process. Heterocoagulation impaired self-assembly of the particles, resulting in a disordered structure. Burn-out of the polymer yielded a random array of YSZ shells. The effect of the filling fraction of YSZ between these shells was explored. YSZ-inverse photonic glass films with a thickness below 40 μm achieved 70% reflectance of the incident radiation over a broad wavelength range between 0.4 and 2.2 μm. The YSZ structures demonstrated structural stability up to 1000 °C and maintained high reflectance up to 1200 °C for several hours, thus enabling applications as broadband reflectors at elevated temperatures.

Low‐Temperature Mullite Formation in Ternary Oxide Coatings Deposited by ALD for High‐Temperature Applications

“…reflectance reduction after heat treatment, several reasons have to be considered: first, the inverse opal structure shrinks during heat treatment and macroscopic cracks originated during the self-assembly [7,8] process (not visible in the small field-of-view in the scanning electron microscopy (SEM)) can open up during sintering [48] ; Second, the texture associated with the new formed grains in the coating (inset in Figure 8d) shall increase the portion of the incident light being scattered; Third, analogous to the results presented by Tétreault et al, [49] the mullite coating can be interpreted as a defect into the alumina inverse opal structure, depending on the thickness and refractive index; Fourth, mullite itself presents a lower refraction index than alumina. [10] In view of that, only coated opals are being compared, hence the comparison of opals composed by different materials could mislead to wrong conclusions.…”

“…Additionally, by combining two or more binary ALD processes in a super cycle ALD process, multicomponent materials can be achieved, such as nanolaminates, doped thin films, and ternary or quaternary oxides. [5] The ability of compositional control of thin films at an atomic level provides the possibility for development of tailor-made atomically mixed systems, pointing to novel materials functionalities.Direct and inverse opals are examples of photonic crystals, which can be manufactured by colloidal self-assembly [6,7] and ALD. [8,9] Its high ordered porosity of interconnects is attractive for a variety of technological applications, such as porous membranes, catalysts, solid oxide fuel cells, and photonics applications.…”

“…Direct and inverse opals are examples of photonic crystals, which can be manufactured by colloidal self-assembly [6,7] and ALD. [8,9] Its high ordered porosity of interconnects is attractive for a variety of technological applications, such as porous membranes, catalysts, solid oxide fuel cells, and photonics applications.…”

High temperature behavior of monodisperse porosity in alumina films

“…The pore periodicity of inverse opals is well-known to affect the propagation of electromagnetic radiation in optical films [2] and has also been utilized for electrochemical applications [4]. Additionally, disordered structures have been considered for random lasing and resonance-dependent Anderson localization [5,6], as well as for omnidirectional reflectors, TBCs [7], and structural coloration [8,9] due to their strong scattering of light.…”

Layout and first results of the nanotomography endstation at the P05 beamline at PETRA III

“…Spherical zirconia particles with a diameter of 2 μm are assembled by drop-casting on a glass substrate [15,16]. This process results in a layer of randomly arranged particles with a thickness t ≈ 35 μm.…”