Inkjet-printed organic photodiodes

Inkjet-printed organic photodiodes are reported, which eliminate the need for photodiode patterning as compared to other solution-based fabrication techniques. Both interlayer and bulk heterojunction ink formulations are optimized to fabricate diodes with low dark currents of 2 μA/cm2 and high external quantum efficiencies of 68.5% at − 5 V reverse bias. The current–voltage characteristics of the printed devices are competitive with photodiodes fabricated with established solution based technologies, such as spray-coating or blading. A comparison of photodiodes fabricated with a variety of solution processes showed that dark current densities are not related to microscale bulk heterojunction roughness.