title: Flexible thermochromic window based on hybridized VO2/graphene.
abstract: Large-scale integration of vanadium dioxide (VO2) on mechanically flexible substrates is critical to the realization of flexible smart window films that can respond to environmental temperatures to modulate light transmittance. Until now, the formation of highly crystalline and stoichiometric VO2 on flexible substrate has not been demonstrated due to the high-temperature condition for VO2 growth. Here, we demonstrate a VO2-based thermochromic film with unprecedented mechanical flexibility by employing graphene as a versatile platform for VO2. The graphene effectively functions as an atomically thin, flexible, yet robust support which enables the formation of stoichiometric VO2 crystals with temperature-driven phase transition characteristics. The graphene-supported VO2 was capable of being transferred to a plastic substrate, forming a new type of flexible thermochromic film. The flexible VO2 films were then integrated into the mock-up house, exhibiting its efficient operation to reduce the in-house temperature under infrared irradiation. These results provide important progress for the fabrication of flexible thermochromic films for energy-saving windows.
authors.affiliation: Electronic Materials and Device Research Center, Korea Electronics Technology Institute, Gyeonggi-do 463-816, Korea.
authors.forename: Hyeongkeun
authors.initials: H
authors.lastname: Kim
authors.forename: Yena
authors.initials: Y
authors.lastname: Kim
authors.forename: Keun Soo
authors.initials: KS
authors.lastname: Kim
authors.forename: Hu Young
authors.initials: HY
authors.lastname: Jeong
authors.forename: A-Rang
authors.initials: AR
authors.lastname: Jang
authors.forename: Seung Ho
authors.initials: SH
authors.lastname: Han
authors.forename: Dae Ho
authors.initials: DH
authors.lastname: Yoon
authors.forename: Kwang S
authors.initials: KS
authors.lastname: Suh
authors.forename: Hyeon Suk
authors.initials: HS
authors.lastname: Shin
authors.forename: TaeYoung
authors.initials: T
authors.lastname: Kim
authors.forename: Woo Seok
authors.initials: WS
authors.lastname: Yang
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D006108:Graphite / Q000737:chemistry*; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012031:Refractometry / Q000295:instrumentation*; D013696:Temperature; D013817:Thermography / Q000295:instrumentation*; D017968:Vanadium Compounds / Q000737:chemistry*
chemical_list: D017968:Vanadium Compounds; D006108:Graphite; C066075:vanadium pentoxide