A modeling approach to understanding OLED performance improvements arising from spatial variations in guest:host blend ratio

Greenberg, M., Sanderson, S., White, R.D., Vamvounis, G., Burn, P.L., and Philippa, B. (2023) A modeling approach to understanding OLED performance improvements arising from spatial variations in guest:host blend ratio. Journal of Chemical Physics, 159. 034101.

PDF (Published Version) - Published Version
Available under License Creative Commons Attribution.

Download (6MB) | Preview
View at Publisher Website: https://doi.org/10.1063/5.0152922


Phosphorescent organic light emitting diodes (OLEDs) suffer from efficiency roll off, where device efficiency rapidly decays at higher luminance. One strategy to minimize this loss of efficiency at higher luminance is the use of non-uniform or graded guest:host blend ratios within the emissive layer. This work applies a multi-scale modeling framework to elucidate the mechanisms by which a non-uniform blend ratio can change the performance of an OLED. Mobility and exciton data are extracted from a kinetic Monte–Carlo model, which is then coupled to a drift diffusion model for fast sampling of the parameter space. The model is applied to OLEDs with uniform, linear, and stepwise graduations in the blend ratio in the emissive layer. The distribution of the guests in the film was found to affect the mobility of the charge carriers, and it was determined that having a graduated guest profile broadened the recombination zone, leading to a reduction in second order annihilation rates. That is, there was a reduction in triplet–triplet and triplet-polaron annihilation. Reducing triplet–triplet and triplet-polaron annihilation would lead to an improvement in device efficiency.

Item ID: 79372
Item Type: Article (Research - C1)
ISSN: 1089-7690
Copyright Information: © 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Funders: Australian Research Council (ARC), Australian Government Research Training Program Scholarship
Projects and Grants: ARC DP210102192, ARC FL160100067
Date Deposited: 20 Jul 2023 04:25
FoR Codes: 40 ENGINEERING > 4016 Materials engineering > 401608 Organic semiconductors @ 100%
SEO Codes: 28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280110 Expanding knowledge in engineering @ 100%
Downloads: Total: 26
Last 12 Months: 21
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page