Design and evaluation of thermally conductive sheet structure to enhance the thermal stability of transparent OLED displays

In transparent organic light-emitting diode (OLED) displays, both optical and thermal properties strongly affect stable performance in various environmental conditions. Though many previous studies have focused on improving the thermal conductivity of the transparent material itself, the current value of 2.5 W/mK [J. Mater. Chem. C4, 9697 (2016)] may not be enough to ensure reliable performance for transparent OLED displays. In this study, we aim to introduce a novel sheet structure based on line patterned thermally conductive material embedded in a transparent polymer sheet. After designing and fabricating the optimized sheet structure, its optical and thermal characteristics were evaluated experimentally. Finally, the thermal conductivity of the developed transparent sheet was measured to be 4.35 W/mK in the louver direction with a transmittance of 75%, improved color uniformity and reduced temperature deviation in the transparent OLED displays.