Tailoring spin mixtures by ion-enhanced Maxwell magnetic coupling in color-tunable organic OLEDs

A new AC-multicolored pixel is demonstrated.

The TEAM: Junwei Xu, Yue Cui, Gregory M Smith, Peiyun Li, Chaochao Dun, Linqi Shao, Yang Guo, Hongzhi Wang, Yonghua Chen, David L Carroll. The work: color agility in OLEDs.

“This represents an entirely new, and efficient way to develop multicolored pixellization. The result will be much higher resolution displays, TVs, iPhones and more.”

The work was performed by a multidisciplinary team of scientists in the US and China. WFU has filed patents on the technology.

ABSTRACT

In this work, we show that the spin dynamics of excitons can be dramatically altered by Maxwell magnetic field coupling, together with an ion-enhanced, low-internal-splitting-energy organic semiconducting emitter. By employing a unique, alternating current (AC)-driven organic electroluminescent (OEL) device architecture that optimizes this magnetic field coupling, almost complete control over the singlet-to-triplet ratio (from fluorescent to phosphorescent emission in a single device) is realized. We attribute this spin population control to magnetically sensitive polaron–spin pair intersystem crossings (ISCs) that can be directly manipulated through external driving conditions. As an illustration of the utility of this approach to spin-tailoring, we demonstrate a simple hybrid (double-layer) fluorescence–phosphorescence (F–P) device using a polyfluorene-based emitter with a strong external Zeeman effect.

you can find out more: 2018/8/1, Light: Science & Applications, Volume 7, Issue 1, Page 46,Nature Publishing Group