H. Dai, M. Spaid
cambrios advanced materials,
Keywords: silver nanowires, transparent conductive films, flexibility
Summary:Curved, flexible, foldable, and stretchable are key technology trends for the next generation displays, touch screens, and wearable electronic devices. One important component used in these devices is an optically transparent conductive electrode. Currently, transparent conductive films based on sputtered metal oxides such as indium tin oxide (ITO) are the most widely used transparent conductive electrodes in display devices. However, ITO is a ceramic material and inherently brittle, which makes it not ideal for flexible and stretchable displays. In this paper we will report a flexible transparent conductive ITO-alternative material, ClearOhm® silver nanowire film, developed by Cambrios Advanced Materials Corporation. ClearOhm® film was wet coated or printed with a formulated dispersion of silver nanowires on clear substrates. It consists of percolated silver nanowire network and has sheet resistances ranging from 5 to 300 ohms/square. The ClearOhm® film has excellent optical properties: > 91% total transmission and < 0.2 % total haze at 70 ohms/square or higher. Moreover, the ClearOhm® film has shown extreme flexibility and bendability, with stable film resistance for >350,000 cycles at 1 mm bend radius. This paper will also discuss the environmental stability of ClearOhm® silver nanowire films in accelerated aging tests, including the elimination of silver nanowire photo-oxidation when exposed to UV light such as sunlight. Due to its high transparency, low resistivity, and low cost, ClearOhm® silver nanowire film has been widely used in touch panels for phones, computers, and large educational boards. With its superior flexibility, the ClearOhm® silver nanowire transparent conductive film is the most promising transparent electrode material for tomorrow’s flexible and bendable devices.