Effect of Sheet Resistance of Indium Tin Oxide Films on Thermal Management in Optoelectronic Devices

Control over the infrared (IR) reflectance and transmittance of an indium tin oxide (ITO) transparent conductive film (TCF) can significantly influence the thermal management of an optoelectronic device containing it, an aspect often overlooked in the existing literature. In this paper, we demonstrate that modulating the sheet resistance is an effective strategy to control the IR reflectance and transmittance of ITO films. As the sheet resistance of an ITO TCF increases, its IR reflectance decreases, while its IR transmittance increases. For example, when considering an ITO TCF reflecting over 60% of thermal radiation, our theoretical and experimental findings suggest that the sheet resistance should not exceed 60 Ω/□. To illustrate the effectiveness of ITO TCFs in blocking thermal radiation, we conducted an experiment by placing one on top of a Pt100 resistance thermometer that was exposed to an IR emitter. The thermometer readings for TCFs with sheet resistances of 14.9, 60.1, and 371 Ω/□ were 33.0, 36.6, and 38.4 °C, respectively. These results demonstrate that modulating the sheet resistance is an effective strategy for optimizing thermal management in various optoelectronic devices.