title: High-performance flexible electrochromic device based on facile semiconductor-to-metal transition realized by WO3·2H2O ultrathin nanosheets.
abstract: Ultrathin nanosheets are considered as one kind of the most promising candidates for the fabrication of flexible electrochromic devices (ECDs) due to their permeable channels, high specific surface areas, and good contact with the substrate. Herein, we first report the synthesis of large-area nanosheets of tungsten oxide dihydrate (WO3·2H2O) with a thickness of only about 1.4 nm, showing much higher Li(+) diffusion coefficients than those of the bulk counterpart. The WO3·2H2O ultrathin nanosheets are successfully assembled into the electrode of flexible electrochromic device, which exhibits wide optical modulation, fast color-switching speed, high coloration efficiency, good cyclic stability and excellent flexibility. Moreover, the electrochromic mechanism of WO3·2H2O is further investigated by first-principle density functional theory (DFT) calculations, in which the relationship between structural features of ultrathin nanosheets and coloration/bleaching response speed is revealed.
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale, University of Science & Technology of China, Hefei, Anhui, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Liang
authors.forename: Jiajia
authors.initials: J
authors.lastname: Zhang
authors.forename: Yingying
authors.initials: Y
authors.lastname: Zhou
authors.forename: Junfeng
authors.initials: J
authors.lastname: Xie
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
authors.forename: Meili
authors.initials: M
authors.lastname: Guan
authors.forename: Bicai
authors.initials: B
authors.lastname: Pan
authors.forename: Yi
authors.initials: Y
authors.lastname: Xie