Polylactide-Perylene Derivative for Blue, Biodegradable Organic Light Emitting Diodes

In this work we demonstrate, for the first time, the use of polylactic acid (PLA) as a biodegradable host matrix for the construction of the active emissive layer of organic light emitting diode (OLED) devices for potential use in bioelectronics. In this preliminary study, we report a robust synthesis of two fluorescent PLA derivatives, pyrene-PLA (AH10) and perylene–PLA (AH11). These materials were prepared by the ring opening polymerization of L-lactide with hydroxyalkyl-pyrene and -perylene derivatives using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as catalyst. OLEDs were fabricated from these materials using a simple device architecture involving a solutionprocessed single-emitting layer in the configuration ITO/PEDOT:PSS/PVK:OXD-7(35%):AH10 or AH11(20%)/TPBi/LiF/Al. The turn-on voltage for the perylene OLED at 10 cd/m2 was around 6 V and a maximum brightness of 1200 cd/m2 at 13 V. The corresponding external quantum efficiency and device current efficiency was 1.5% and 2.8 cd/A respectively. In summary, this study provides proof of principle that OLEDs that can be constructed from PLA, a readily available and renewable bio-source.