Highly efficient inverted polymer-based optoelectronic devices via amine-based interfacial molecules

Abstract

We demonstrate highly efficient inverted polymer-based light-emitting diodes (iPLEDs) and inverted polymerbased solar cells (iPSCs) by employing series of amine-based interfacial molecules (AIMs) containing various number of amine groups. Our method provides a simple and efficient processing as well as effective tunability of energy level at the interface between the ZnO and the active layer depending on the number of amine groups of AIMs. As the number of amine groups increases, the work functions (WFs) of AIMs-modified ZnO gradually shift to the vacuum level, which reduces the energy barrier effectively between the ZnO and the active layer. In addition, AIMs treatment passivates the defect sites of the ZnO and blocks the holes, leading to enhanced device performances in both iPLEDs and iPSCs. In particular, optimized iPLEDs with PEHA (6N) show the maximum luminance of 99,300 cd m-2, LE of 23.1 cd A-1, PE of 8.83 lm W-1 and EQE of 8.40 %, which are enhanced by approximately 30-fold, 32-fold, 38-fold and 30-fold, respectively, compared to the reference device. For iPSCs, optimized iPSCs with DETA (3N) showed the PCE of 9.04%, which is enhanced by roughly 30 %, compared to that of the reference devices. Furthermore, our approach is a promising method for high device performances in organic based optoelectronic devices.