What is the most promising alternatives to ITO as a flexible transparent electrode? There are many substitutes to ITO as flexible transparent electrodes such as conducting polymers, SWCNTs, graphene, and silver nanowires. Each has its own merits. In terms of the transparency, conductivity, smoothly surface and stability, none of them can be comparable to the ITO. Now it seems more work to focus on very thin metal composites layer or thin metal grids for flexible electrodes. The question is how stable it is if using them as a flexible electrode to make electronic devices such as flexible OLEDs or solar cells? Much appreciated if any one could contribute to his thoughts.