Conductive cooling in white organic light emitting diode for enhanced efficiency and life time

We demonstrate white organic light emitting diodes with enhanced efficiency (26.8 lm/W) and life time (similar to 11 000 h) by improved heat dissipation through encapsulation composed of a metal (Cu, Mo, and Al) and mica sheet joined using thermally conducting epoxy. Finite element simulation is used to find effectiveness of these encapsulations for heat transfer. Device temperature is reduced by about 50% with the encapsulation. This, consequently, has improved efficiency and life time by about 30% and 60%, respectively, with respect to glass encapsulation. Conductive cooling of device is suggested as the possible cause for this enhancement. (C) 2015 AIP Publishing LLC.