High-performance laminated NiO film striking a balance between the color-changing capability and cycling stability and its real application in bistable display

Electrochromic (EC) technology is highly desirable in energy-conserving bistable displays as it can dynamically modulate color changes under small voltages and maintain the changed color after the power is cut off. For its practical application, low cost, easy fabrication and good durability are crucial. The shoulder-by-shoulder EC structure is talented in achieving low cost and easy fabrication because the counter electrode and its corresponding conductive layer were not necessary in it. Moreover, the EC material determines the stability against light radiation and long-term use. Herein, crystalline NiO films were selected owing to their gifted structure stability in crystalline state, and were fabricated through the sputtering process at a high deposition rate of 50 nm/min. The NiO film was further optimized to a laminated structure with the room-temperature-deposited NiO at the top and the 100 degree celsius-deposited NiO at the bottom adjacent to ITO substrates as the adhesive layer. A high optical modulation rate of 59 % and excellent cycling stability with only 6 % degradation over 3000 cycles were achieved. Bistable price tags were then designed using the high-performance laminated NiO film and shoulder-by-shoulder EC structure. Thus fabricated EC material will significantly advance the applications of EC technology in various intelligent display scenarios.