High-performance transparent film heater using random mesowire silver network

In this research, we demonstrate a cost-effective method of developing a high temperature transparent heater by creating mesoscale (1-5m diameter) silver (Ag) wire network on glass. A colloidal solution of ethanol and cerium oxide (CeO2) is used to create a sacrificial template onto which Ag (100nm) was deposited using electron beam (EB) evaporation. EB deposition parameters are critically optimized so that Ag wires are annealed instantly having rigid adherence to the substrate surface. A highly interconnected and continuous Ag network is obtained exhibiting transmittance up to 70% and sheet resistance of 1.13/sq, making it suitable for optoelectronic applications. This transparent conductor serves as a transparent heater when a DC voltage is applied to it, generating temperatures more than 200 degrees C at an operating voltage of just 4V. This unique electro-thermal property can be attributed to the triangular junctions of Ag wire network that act as a micro-welding centers which impede the transport current path, favoring resistive Joules heating.