Micro-nano dual-scale embedded graphene/Ag architectures for flexible low-voltage-driven transparent electrothermal films

Transparent electrodes are the key elements of flexible optoelectronic devices. Graphene is a promising electrode material due to its excellent optical, electrical and mechanical properties. However, finding a low-cost and high-efficiency strategy to fabricate graphene transparent electrodes has been challenging. In this work, combining UV imprinting with a blade-coating process, without using expensive equipment and complex processes, micro-nano dual-scale embedded graphene/silver (Ag) architectures are designed to fabricate high-performance flexible transparent electrodes, thus realizing low-voltage-driven transparent electrothermal films. Optical transmittance is realized by the mesh treatment of the film structure. The Ag nanoparticles can fully connect the graphene sheets for optimizing the electrical conductivity. With an optical transmittance of 89.9%, the embedded graphene/Ag mesh electrothermal film is capable of reaching temperatures above 70 °C at a low voltage of 3 V. Compared with the graphene mesh electrothermal film, the driven voltage is greatly reduced, which means lower energy consumption. Flexible smart windows based on the embedded graphene/Ag mesh electrothermal film can realize color change under the driven voltage of two batteries in series, indicating great application potential in flexible electronic devices of low-voltage-driven smart windows.