Surface engineering on continuous VO 2 thin films to improve thermochromic properties: Top-down acid etching and bottom-up self-patterning.

Surface engineering is an effective method to improve the thermochromic performance of VO2 . In this paper, an acid-etching top down method was proposed to tailor the VO2 surface morphology from the continuous dense-packed surface to patterned structure, which exhibited the enhanced integrated visible transmittance (Tlum ) and the enlarged solar modulating abilities (ΔTsol ). Moreover, a self-patterning approach was also illustrated to improve the thermochromic properties. The proposed surface engineering methods represent a facile and cost-effective approach for enhancing thermochromic properties that could promote the application of VO2 thin films in smart windows.