In-operando investigation of Purcell effect on efficiency roll-off in top-emitting phosphorescent organic light emitting diodes

Mina Riahi; Kou Yoshida; Liam G. King; Ifor D. W. Samuel

doi:10.1016/j.synthmet.2025.117848

In-operando investigation of Purcell effect on efficiency roll-off in top-emitting phosphorescent organic light emitting diodes

Mina Riahi, Kou Yoshida, Liam G. King, Ifor D. W. Samuel^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

Efficiency roll-off is a major issue for applications of organic light emitting diodes (OLEDs) that require high brightness. The underlying processes leading to efficiency roll-off in phosphorescent OLEDs include triplet-polaron (TPA) and triplet-triplet annihilation (TTA). Hence, decreasing the triplet exciton lifetime by enhancing radiative decay rates can be an effective method to manage efficiency roll-off in phosphorescent OLEDs. Here we use in-operando measurement to study the Purcell effect and engineer efficiency roll-off. By changing the cavity parameters and measuring electroluminescence (EL) and photoluminescence (PL) on operating devices, we find that devices with higher Purcell factor have a smaller efficiency roll-off, suggesting a route to improve the performance of OLEDs in high brightness applications.

Original language	English
Article number	117848
Number of pages	6
Journal	Synthetic Metals
Volume	312
Early online date	20 Feb 2025
DOIs	https://doi.org/10.1016/j.synthmet.2025.117848
Publication status	E-pub ahead of print - 20 Feb 2025

Keywords

OLED
Microcavity
Triplet
Exciton lifetime

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Riahi_2025_SM_In-operando-investigation-Purcell-effect-organic-LEDs_CC
© 2025 The Authors. This is an open access article distributed under the terms of the Creative Commons CC-BY license (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Final published version, 2.91 MBLicence: CC BY

EPSRC-JSPS Core-to-core Grant: EPSRC-JSPS Core-to-Core Grant Application
Samuel, I. D. W. (PI)
1/08/18 → 31/07/23
Project: Standard

In-operando Investigation of Purcell effect on Efficiency Roll-off in Top-emitting Phosphorescent Organic Light Emitting Diodes (dataset)
Riahi, M. (Creator), Yoshida, K. (Creator), King, L. (Creator) & Samuel, I. D. W. (Creator), University of St Andrews, 21 Feb 2025
DOI: 10.17630/ced2ff75-69e1-4887-b256-4756578fd280
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Cite this

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title = "In-operando investigation of Purcell effect on efficiency roll-off in top-emitting phosphorescent organic light emitting diodes",

abstract = "Efficiency roll-off is a major issue for applications of organic light emitting diodes (OLEDs) that require high brightness. The underlying processes leading to efficiency roll-off in phosphorescent OLEDs include triplet-polaron (TPA) and triplet-triplet annihilation (TTA). Hence, decreasing the triplet exciton lifetime by enhancing radiative decay rates can be an effective method to manage efficiency roll-off in phosphorescent OLEDs. Here we use in-operando measurement to study the Purcell effect and engineer efficiency roll-off. By changing the cavity parameters and measuring electroluminescence (EL) and photoluminescence (PL) on operating devices, we find that devices with higher Purcell factor have a smaller efficiency roll-off, suggesting a route to improve the performance of OLEDs in high brightness applications.",

keywords = "OLED, Microcavity, Triplet, Exciton lifetime",

author = "Mina Riahi and Kou Yoshida and King, {Liam G.} and Samuel, {Ifor D. W.}",

note = "Funding: The authors are grateful to the Engineering and Physical Sciences Research Council for support from grants EP/R035164 and EP/Y037243/01.",

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T1 - In-operando investigation of Purcell effect on efficiency roll-off in top-emitting phosphorescent organic light emitting diodes

AU - Riahi, Mina

AU - Yoshida, Kou

AU - King, Liam G.

AU - Samuel, Ifor D. W.

N1 - Funding: The authors are grateful to the Engineering and Physical Sciences Research Council for support from grants EP/R035164 and EP/Y037243/01.

PY - 2025/2/20

Y1 - 2025/2/20

N2 - Efficiency roll-off is a major issue for applications of organic light emitting diodes (OLEDs) that require high brightness. The underlying processes leading to efficiency roll-off in phosphorescent OLEDs include triplet-polaron (TPA) and triplet-triplet annihilation (TTA). Hence, decreasing the triplet exciton lifetime by enhancing radiative decay rates can be an effective method to manage efficiency roll-off in phosphorescent OLEDs. Here we use in-operando measurement to study the Purcell effect and engineer efficiency roll-off. By changing the cavity parameters and measuring electroluminescence (EL) and photoluminescence (PL) on operating devices, we find that devices with higher Purcell factor have a smaller efficiency roll-off, suggesting a route to improve the performance of OLEDs in high brightness applications.

AB - Efficiency roll-off is a major issue for applications of organic light emitting diodes (OLEDs) that require high brightness. The underlying processes leading to efficiency roll-off in phosphorescent OLEDs include triplet-polaron (TPA) and triplet-triplet annihilation (TTA). Hence, decreasing the triplet exciton lifetime by enhancing radiative decay rates can be an effective method to manage efficiency roll-off in phosphorescent OLEDs. Here we use in-operando measurement to study the Purcell effect and engineer efficiency roll-off. By changing the cavity parameters and measuring electroluminescence (EL) and photoluminescence (PL) on operating devices, we find that devices with higher Purcell factor have a smaller efficiency roll-off, suggesting a route to improve the performance of OLEDs in high brightness applications.

KW - OLED

KW - Microcavity

KW - Triplet

KW - Exciton lifetime

U2 - 10.1016/j.synthmet.2025.117848

DO - 10.1016/j.synthmet.2025.117848

M3 - Article

SN - 0379-6779

VL - 312

JO - Synthetic Metals

JF - Synthetic Metals

M1 - 117848

ER -

In-operando investigation of Purcell effect on efficiency roll-off in top-emitting phosphorescent organic light emitting diodes

Abstract

Keywords

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Projects

EPSRC-JSPS Core-to-core Grant: EPSRC-JSPS Core-to-Core Grant Application

Datasets

In-operando Investigation of Purcell effect on Efficiency Roll-off in Top-emitting Phosphorescent Organic Light Emitting Diodes (dataset)

Cite this