Mesoscopic modelling of 2-CN-PPV/PPV polymer LED

Abstract

Although optoelectronic devices made of polymers are very attractive ones (low cost, easy to make), problems related to charge transport, exciton quenching, among others, can be an obstacle for their performance. The use of heterojunctions made of two polymers can be a strategy for improving the efficiency of polymer light emitting diodes (PLEDs) at low bias. Here we present a theoretical study of the influence of bilayer structure in a PLED made of PPV and 2-CN-PPV, by adopting a mesoscopic approach. Our results show that the presence of the polymer/polymer interface improves charge injection and leads to a confinement of charges near it, which will increase the number recombination events in the middle of the device compared to the equivalent single-layer PLEDs.