柔性铜网栅基透明导电薄膜制备及疲劳损伤机理研究

Flexible copper mesh-based transparent conductive film, with attributes of cost-effectiveness, excellent ductility, tunable optical and electrical properties, etc., is a novel and viable promising candidate for substitution of ITO as transparent conductor used extensively in touch panel and photovoltaic battery production. However, the adhesion of copper film on flexible PET substrate is very poor, and a large number of pinholes can be formed during deposition. Moreover, the copper film is vulnerable to be oxidized, and can be damaged after repeated mechanical deformation, which will decrease the sensitivity and lead to the malfunction of the device. Herein, we will investigate the optical-electrical and environment conditioning properties of the copper mesh-based transparent conductive film systematically. More importantly, it is our ultimate purpose to address the pinhole problem and to improve the adhesion of the copper layer on PET substrate as well as to enhance the fatigue behavior of the end product, which are the keys for application in touch panel and photovoltaic battery as transparent conductor. The purpose of this project is threefold. Firstly, we will study the surface pretreatment condition for flexible PET substrate to improve the adhesion of the over growing copper film. Secondly, we will investigate the composition of the copper alloy and the protective film for copper mesh together with copper film deposition condition, in order to obtain the parameters for copper mesh-based transparent conductive film production, which possesses high density, good environment stability as well as excellent fatigue behavior. Lastly, we will expound the underlying mechanism of the fatigue failure and electro-migration of the flexible copper mesh-based transparent conductive film by analyzing the experiment results together. These research results will provide reliable experimental evidence and theoretical basis for application of copper mesh-based transparent conductive film in information and energy field, especially in touch panel and photovoltaic battery production.

柔性铜网栅基透明导电薄膜由于具有成本低廉、延展性好以及光学与电学性能可调等特性，为替代ITO透明导电薄膜在触摸屏、光伏电池等领域的应用提供了一种新颖可行的方案。但是，铜金属薄膜与柔性PET衬底附着力差，薄膜沉积时易形成大量针孔且易氧化，在反复拉压弯曲形变和力/电综合作用下易发生疲劳失效，从而降低敏感度，影响器件的正常工作。本项目以柔性铜网栅基透明导电薄膜为研究对象，以铜网栅的光电特性及环境稳定性为研究重点，以改善柔性衬底上铜网栅缺陷、附着力以及反复弯曲形变的疲劳损伤特性为目标，以期获得性能优异的铜网栅基透明导电薄膜，实现其在触摸屏等产品中的实际应用。本项目拟从材料改性入手，通过对铜合金成分及薄膜制备工艺研究，获得制备致密度高、环境稳定性好、抗疲劳特性优良的铜网栅基透明导电薄膜的关键参数，阐明柔性铜网栅薄膜的疲劳损伤机理及电迁移机制，为其在信息、能源等领域的广泛应用提供实验依据和理论指导。

柔性铜网栅基透明导电薄膜由于具有成本低廉、延展性好以及光学与电学性能可调等特性，为替代ITO透明导电薄膜在触摸屏、光伏电池等领域的应用提供了一种新颖可行的方案。但是，铜金属薄膜与柔性PET衬底附着力差，薄膜沉积时易形成大量针孔且易氧化，在反复拉压弯曲形变和力/电综合作用下易发生疲劳失效，从而降低敏感度，影响器件的正常工作。本项目从材料改性入手，研究了不同预处理工艺（包括气氛、功率等）对薄膜附着力的影响，获得了具有较强亲水性质的表面（水接触角<35°），通过对铜合金成分及薄膜制备工艺研究，获得制备致密度高、环境稳定性好、抗疲劳特性优良的铜网栅基透明导电薄膜的关键参数，获得了抗氧化性能优异的表面防护层（CuO），且能有效降低金属的反射率（<3%），制备出了高透过率(T>95%)、低电阻(Rs<30Ω/□)的柔性铜网栅透明导电薄膜，阐明柔性铜网栅薄膜的疲劳损伤机理及电迁移机制，为其在信息、能源等领域的广泛应用提供实验依据和理论指导。