An all-thin-film inorganic electrochromic device monolithically fabricated on flexible PET/ITO substrate by magnetron sputtering

Abstract In this study, an all-thin-film inorganic electrochromic device was monolithically fabricated on a 10 cm×8 cm flexible PET/ITO substrate by magnetron sputtering process at room temperature. The device has a complementary structure and consists of five thin films. Tungsten oxide (WO 3 ) and nickel oxide (NiO x ) act individually as complementary electrochromic layers. Lithium tantalate (LiTaO 3 ) plays the role of Li + ions conductor layer and both indium tin oxides (ITO) are adopted as inter-counter transparent conductive electrodes. The complementary device with configuration ITO/NiO x /LiTaO 3 /WO 3 /ITO has high optical modulation approximating 63% in the range from 400 to 1600 nm and shows the coloration efficiency as high as 68.5 cm 2  C −1 . In addition, the response characteristic is investigated for the electrochromic process.