| 초록 |
Electrochromic (EC) and thermochromic (TC) materials exhibit reversible change of their optical transmittances in response to applied electric field and temperature, respectively. Here, we fabricated a monolithic all-solid-state form of EC-TC hybrid device on a Polyethylene terephthalate (PET) substrate for the selective modulation of visible and near-infrared transmittances and mechanical flexibility. EC-TC hybrid device consists of an tungsten oxide (WO3) for EC layer in contact with a Li based gel electrolyte adjacent to vanadium oxide (VO2) for TC layer, and these layers are sandwiched between the transparent conducting layers of indium tin oxide (ITO) on PET. PET is one of the most popular alternatives to rigid glass as a substrate material owing to the increasing demand for flexible, lightweight, and cost-effective transparent electrodes. However, the growth of VO2 directly on PET is technologically restricted because of PET’s lack of thermal robustness to withstand the high-temperature thermal treatment required for VO2 phase. To overcome high-temperature thermal treatment, the VO2 film were deposited ITO/Cu foil and then transfer onto a PET substrate using standard wet etching transfer method. Finally, the flexible EC-TC hybrid device was fabricated by laminating the WO3/ITO/PET and VO2/ITO/PET films using Li-based polymeric solid-state electrolyte. The TC behavior of the EC-TC hybrid device in its colored and bleached states indicates that luminous and solar transmittance of the device can be actively regulated by oneself with increasing and decreasing temperature. Finally, four-different optical states were realized by using EC reaction and TC behavior selectively on flexible PET substrate. This PET based hybrid device may open new avenues in the development of flexible electrochromic and thermochromic devices. |
