Comprehensive optical and electrical characterization and evaluation of organic light-emitting diodes for visible light communication

In recent years, we have seen an increased use of organic light-emitting diodes (OLEDs) for illumination in indoor environments due to their softer light compared with the conventional inorganic LEDs. In addition, OLEDs have been reported in visible light communication (VLC) systems, specifically for applications with lower data rates, such as information boards, camera communications, and positioning. However, OLEDs need extensive electrical and optical characterization if they are going to be fully exploited in VLC. We investigated characteristics of a range of flexible and rigid OLEDs and compared them with inorganic LEDs. We show that OLEDs have highly linear power–current characteristics, and compared with rigid OLEDs with beam patterns closely matching the Lambertian profile, the flexible OLED’s radiation pattern is wider. Based on the measured experimental data, a new expression for the OLED’s beam pattern, which follows the three-term Gaussian profile, is proposed. Moreover, we show that using larger size OLEDs in VLC links offers improved bit error rate performance over a wide tilting angle of up to 80 deg and a transmission path length of up to 60 cm.