Metal-Oxide Based Transparent Heater with Interdigitated Electrodes

This study aimed to compare and analyze various transparent heaters to ascertain their potential applications in smart windows. Transparent heaters have promising applications in fields where visibility is essential. Their applications in buildings and vehicles offer significant advantages. A major benefit is their ability to operate with minimal energy consumption, thereby contributing to energy saving for heating. Additionally, their transparency provides superior visual aesthetics, and their high infrared reflectivity is effective in reducing heat transfer through glasses by loss, helping maintain the quality of indoor temperatures and environments. The transparent heater functions according to the Joule heating principle, in which reducing the resistance and enhancing the current flow under a specific voltage leads to increased heat production. For active transparent heaters, the optical and electrical profiles of a single ITO film and ITO/Ag/ITO (oxide/metal/oxide, OMO) structures were investigated. The OMO structure provides a substantially low resistance (2.2 Ω/□) and high optical transmittance (76%). An interdigitated electrode was designed to provide multiple current paths for improving current flow. The suitability of the structures was assessed by comparing the results of each characteristic. OMO-structured transparent heaters exhibit excellent optical and electrical properties, making them suitable for application as films on glass in the structural, surface, and automotive industries.