Electro-thermal effects in large area white-organic light emitting diodes

Abstract

OLEDs for lighting became of high relevance, although challenges in the uniformity and thermal effects. In this work, White-OLEDs with 16 cm2 emitting area was made with wide color temperature range (3200 K to 10500K) and color rendering index near 90. The CIE coordinates are stable with applied voltage. Thermal images shows 60°C in the center decreasing to 35°C at the border. This effect was study by a scalar electro-thermal model, considering the substrate, electrodes and organic layers. The thermal changing ratio in the series resistance and forward voltage obtained was of - 70 mΩ/°C and -10 mV/°C respectively.