Thesis defense of Guillaume BOUDAN

Thesis defense of Guillaume BOUDAN, PhD student in the Nanophotonics group of the Laboratoire Charles Fabry, on Tuesday 17 December 2024 at 10:30am in the Auditorium of the Institut d'Optique Graduate School in Palaiseau, on the topic: "An effective method to control radiative exchanges between an object and its environment is to modify its emissivity. Thermochromic materials with metal-insulator transition (MIT), whose optical properties vary in the infrared depending on the temperature, offer a promising solution for achieving this control. Among these materials, vanadium dioxide (VO₂), which undergoes a phase transition near room temperature, enables the design of innovative composite materials for passive control of radiative fluxes. This thesis focuses, on the one hand, on the design of a new VO₂-based double glazing system, self-regulated by the greenhouse effect, aimed at addressing the challenges of passive thermal management in buildings. On the other hand, it explores the design of a VO₂-based multilayer photonic switch exhibiting positive differential emissivity. This device is capable of emitting a significant radiative heat flux beyond the critical temperature of VO₂ while maintaining low emission below this threshold. Fully temperature-controlled, this coating paves the way for numerous applications in radiative cooling and thermal protection.".