A leaf vein-like hierarchical silver grids transparent electrode towards high-performance flexible electrochromic smart windows

用于柔性智能变色玻璃的叶脉状分级银网络透明电极

As essential components of numerous flexible and wearable optoelectronic devices,the flexible transparent conducting electrodes(TCEs)with sufficient optical transmittance and electric conductivity become more and more important.In this work,we fabricated a large-area flexible TCE based on leaf vein-like hierarchical metal grids(HMG)comprising of mesoscale"trunk"and microscale"branches".The selfformed branched grids made the conducting paths distributing uniformly while the laser-etching trunk grids enabled to transport the collected electrons across long-distance.The Ag HMG exhibited high optical transmittance(-81%)with low sheet resistance(1.36Ωsq-1,which could be simply optimized through adjusting the grids’widths,spaces,and the sizes of the TiO2 colloidal crackle patterns.In addition,on the basis of such advanced HMG electrode,flexible electrochromic devices(ECDs)with remarkable cyclic performance were fabricated.The HMG with high transparency,conductivity,and flexibility provides a promising TCE for the next-generation flexible and wearable optoelectronic devices.

呈现出可逆颜色变化的智能窗户可调节阳光的透射,节省大量的能耗.目前,在众多智能玻璃中,柔性电致变色器件由于可实现卷对卷生产,良好的控制性以及与其他能源(太阳能电池和锂电池)的兼容性而受到广泛关注.因此,作为柔性电致变色器件不可或缺的部分,柔性透明电极变得越来越重要.本文基于叶脉状的分层金属网络构造了大面积的柔性透明电极,该多级网络由介观尺度的"树干"和微观尺度的"分支"组成.自发形成的"分支"使导电路径均匀分布,而激光蚀刻的"树干"则能够将收集的电子进行远距离传输.该透明电极表现出高的透光率(~81%)和低的电阻(1.36Ωsq–1),并可通过调整网格的宽度、边长和裂纹图案的大小来优化性能.在此基础上,制造了具有显著循环性能的柔性电致变色器件.具有高透明度、导电性和柔韧性的多级银网络透明电极未来将可能在下一代柔性可穿戴光电设备中有广泛的应用前景.