Samsung Finds Reason For Blue PHOLED Decline

Samsung Electronics is working with the Ewha Womans University in Korea to understand the mechanism for the degradation of the performance of blue phosphorescent OLED materials and the group has published a paper on Nature Communications.

The study found that there is a relationship between the rate constants for charge recombination by back electron transfer (kBeT) and device lifetimes. The findings demonstrate the importance of controlling exciton-induced electron transfer, and provide novel strategies to design materials for long-lifetime blue electrophosphorescence devices, according to the researchers.

Exciton-induced generation of polaron pairs. Electronic processes for the charge-neutral, exciton-mediated generation of radical ion pairs within an emitting layer consisting of a host and a dopant. Direct formation of a dopant exciton (e.g., dopant*) is not included, because intermolecular electron transfer between a host and a dopant exciton is usually forbidden due to negative driving forces

Analyst Comment

The science in this paper went well beyond this editor’s pay grade, but a fundamental undestanding of how and why phosporescent OLEDs deteriorate is clearly very important for the future of OLED displays and lighting. (BR)