Effect of Mie Scattering on Thermochromic Performance of Branched VO2 Prepared by One-Step Hydrothermal Method

In this work, gram-scale branched-VO2 (B-VO2) was synthesized via a mild one-step hydrothermal route, and the corresponding phase transition, optical and electrical performances of B-VO2 were investigated. The differential scanning calorimeter (DSC) results revealed the defect mediated phase transition behavior of B-VO2. The optical studies demonstrated an analogous negative thermochromic performance of B-VO2, which was ascribed to the intense Mie scattering effect. While, ball milling treatment was an effective way to restore the regular thermochromic property, and the ball-milled VO2 (BM-VO2) displayed a 6.3 % increasement of the solar modulation ability. The BM-VO2 films on flexible PET and PI substrates demonstrated both energy-saving and UV-shielding functions. The temperature dependent resistivity displayed about two orders of magnitude change during the phase transition of VO2.