Simultaneous control of carrier transport and film polarization of emission layers aimed at high-performance OLEDs.

ABSTRACT: The orientation of a permanent dipole moment during vacuum deposition results in the occurrence of spontaneous orientation polarization (SOP). Previous studies reported that the presence of SOP in organic light-emitting diodes (OLEDs) lowers electroluminescence efficiency because electrically generated excitons are seriously quenched by SOP-induced accumulated charges. Thus, the SOP in a host:guest-based emission layer (EML) should be finely controlled. In this study, we demonstrate the positive effect of dipole-dipole interactions between polar host and polar emitter molecules on the OLED performance. We found that a small-sized polar host molecule that possesses both high molecular diffusivities and moderate permanent dipole moment, well cancels out the polarization formed by the SOP of

SUBMITTER: Tanaka M 

PROVIDER: S-EPMC11252288 | biostudies-literature | 2024 Jul

REPOSITORIES: biostudies-literature