VO2 films obtained by V2O5 nanoparticle suspension reduction

Shian Guan (1) , Manuel Gaudon (1) , Aline Rougier (1) , Etienne Duguet (1) , Etienne Durand (1) , Alexandre Fargues (1) , Oudomsack Viraphong (1) , Nicolas Penin (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Applications of vanadium dioxide, VO2 , able to modulate near-infrared radiation by changing from a transparent to a reflective/absorptive state, remain limited by its shaping as transparent films. In this work, a V 2 O 5 @PVP core-shell structure is designed prior to the formation of island-structured VO 2 films. Poly(N-vinyl-2-pyrrolidone) (PVP) is used as a surface stabilizer for the preparation of V2O5 NP suspensions; additionally, PVP acts as a reducing agent during the film post-annealing process, helping the V2O5 VO transformation under dynamic vacuum. Using in situ TG-FTIR characterization, the reducing mechanism is carefully discussed and analyzed. Finally, a uniform VO 2 film is fabricated with an attractive gray color and excellent thermal stability. Three strategies with various sintering parameters are used to optimize the film's morphology, i.e., surface coverage. In the last strategy, the thermochromic behavior of the designed island-structure VO2 film is simulated based on Mie scattering theory in consideration of surface coverage and "island" particle size fitting with our experiments. This pioneering work provides guidance for future studies on discontinuous VO 2 films.

Domaines: Matériaux

Shian Guan, Manuel Gaudon, Aline Rougier, Etienne Duguet, Etienne Durand, et al.. VO2 films obtained by V2O5 nanoparticle suspension reduction. Optical Materials, 2022, 127, 112117 (10 p.). ⟨10.1016/j.optmat.2022.112117⟩. ⟨hal-03622138⟩