Thin Coatings of Cerium Oxide Nanoparticles with Anti-Reflective Properties

Laura Romasanta (1, 2) , Lauriane D’alençon (2) , Sara Kirchner (3) , Christophe Pradere (4) , Jacques Leng (5)

1 UB - Université de Bordeaux
2 Solvay (France)
3 LGC - Laboratoire de Génie Chimique
4 I2M - Institut de Mécanique et d'Ingénierie de Bordeaux
5 SUPA School of Physics and Astronomy [Edinburgh]

Cerium oxide, in addition to its catalytic properties, is also known for its optical properties such as ultraviolet (UV) radiation filtering and a relatively high refractive index (n > 2), which makes it an excellent candidate for multifunctional coatings. Here, we focus on the optical properties of thin deposits (2 µm) of densely packed CeO 2 nanoparticles, which we assemble using two evaporation-based techniques: convective self-assembly (CSA, a type of very slow blade-coating) to fabricate large-scale coatings of controllable thickness-from tens of nanometres to a few micrometers-and microfluidic pervaporation which permits us to add some micro-structure to the coatings. Spectroscopic ellipsometry yields the refractive index of the resulting nano-porous coatings, which behave as lossy dielectrics in the UV-visible regime and loss-less dielectrics in the visible to infra-red (IR) regime; in this regime, the fairly high refractive index (≈1.8) permits us to evidence thickness-tunable anti-reflection on highly refractive substrates, such as silicon, and concomitant enhanced transmissions which we checked in the mid-IR region.

Mots clés: Cerium oxide nanoparticles; anti-reflection; self-assembly; microfluidics; convective self-assembly

Domaines: Physique [physics]

Laura Romasanta, Lauriane D’alençon, Sara Kirchner, Christophe Pradere, Jacques Leng. Thin Coatings of Cerium Oxide Nanoparticles with Anti-Reflective Properties. Applied Sciences, 2019, 9 (18), pp.3886. ⟨10.3390/app9183886⟩. ⟨hal-02369444⟩