A saturated red color converter for visible light communication using a blend of star-shaped organic semiconductors

We report a study of blends of semiconducting polymers as saturated red color converters to replace commercial phosphors in hybrid Light emitting diodes (LEDs) for visible light communication (VLC). By blending two star-shaped organic semiconductor molecules, we found a near complete energy transfer (>90% efficiency) from the green-emitting truxene-cored compound T4BT-B to the red-emitting boron dipyrromethene (BODIPY) cored materials. Furthermore, we have demonstrated the capability of these materials as fast color converters for VLC by measuring their intrinsic optical modulation bandwidth and data rate. The measured 3 dB modulation bandwidth of blends (∼55 MHz) is more than 10 times higher than commercially available LED phosphors and also higher than the red-emitting BODIPY color converter alone in solution. The data rate achieved with this blend is 20 times higher than measured with a commercially available phosphor based color converter