Controlling singlet-triplet splitting in carbazole-oxadiazole based bipolar phosphorescent host materials

Paul Kautny; Zhongbin Wu; Berthold Stöger; Antoine Tissot; Ernst Horkel; Jiangshan Chen; Dongge Ma; Hans Hagemann; Johannes Fröhlich; Daniel Lumpi

doi:10.1016/j.orgel.2014.11.027

Controlling singlet-triplet splitting in carbazole-oxadiazole based bipolar phosphorescent host materials

Paul Kautny
, Zhongbin Wu
, Berthold Stöger
, Antoine Tissot
, Ernst Horkel
, Jiangshan Chen
, Dongge Ma
, Hans Hagemann
, Johannes Fröhlich
, Daniel Lumpi

TU Wien
CAS - Changchun Institute of Applied Chemistry
University of Geneva

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

15 Scopus citations

Abstract

A rational molecular design strategy for carbazole-oxadiazole based bipolar host materials was developed to improve the device efficiency of blue phosphorescent organic light-emitting diodes (PHOLED). Steric effects of strategically placed methyl groups led to an increase of triplet energies (o-2MPCzPOXD: 2.66 eV and o-3MPCzPOXD: 2.73 eV versus the initial host material o-PczPOXD: 2.62 eV) while less pronouncedly affecting singlet energies and, therefore, retaining low driving voltages, high power efficiencies and remarkably low efficiency roll-offs in PHOLEDs. The maximum quantum efficiencies (EQE) for blue devices (FIrpic) were significantly raised for o-2MPCzPOXD (13.6%) and o-3MPCzPOXD (11.5%) versus o-PCzPOXD (9.0%) although yielding comparable values for green devices (Ir(ppy)₃; 12.9% and 15.4% versus 13.2%). Supported by theoretical calculations a structure-property relationship was established from photo-physical properties, PHOLED performance measurements and structural characterization from single crystal data.

Original language	English
Pages (from-to)	216-228
Number of pages	13
Journal	Organic Electronics
Volume	17
Issue number	1
DOIs	https://doi.org/10.1016/j.orgel.2014.11.027
State	Published - 2015
Externally published	Yes

Keywords

High triplet energy
Low efficiency roll-off
PHOLED
Sterically induced torsion
Structure-property relationship

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@article{90090ce0a2f74b8cb22b867511cf57df,

title = "Controlling singlet-triplet splitting in carbazole-oxadiazole based bipolar phosphorescent host materials",

abstract = "A rational molecular design strategy for carbazole-oxadiazole based bipolar host materials was developed to improve the device efficiency of blue phosphorescent organic light-emitting diodes (PHOLED). Steric effects of strategically placed methyl groups led to an increase of triplet energies (o-2MPCzPOXD: 2.66 eV and o-3MPCzPOXD: 2.73 eV versus the initial host material o-PczPOXD: 2.62 eV) while less pronouncedly affecting singlet energies and, therefore, retaining low driving voltages, high power efficiencies and remarkably low efficiency roll-offs in PHOLEDs. The maximum quantum efficiencies (EQE) for blue devices (FIrpic) were significantly raised for o-2MPCzPOXD (13.6\%) and o-3MPCzPOXD (11.5\%) versus o-PCzPOXD (9.0\%) although yielding comparable values for green devices (Ir(ppy)3; 12.9\% and 15.4\% versus 13.2\%). Supported by theoretical calculations a structure-property relationship was established from photo-physical properties, PHOLED performance measurements and structural characterization from single crystal data.",

keywords = "High triplet energy, Low efficiency roll-off, PHOLED, Sterically induced torsion, Structure-property relationship",

author = "Paul Kautny and Zhongbin Wu and Berthold St{\"o}ger and Antoine Tissot and Ernst Horkel and Jiangshan Chen and Dongge Ma and Hans Hagemann and Johannes Fr{\"o}hlich and Daniel Lumpi",

year = "2015",

doi = "10.1016/j.orgel.2014.11.027",

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T1 - Controlling singlet-triplet splitting in carbazole-oxadiazole based bipolar phosphorescent host materials

AU - Kautny, Paul

AU - Wu, Zhongbin

AU - Stöger, Berthold

AU - Tissot, Antoine

AU - Horkel, Ernst

AU - Chen, Jiangshan

AU - Ma, Dongge

AU - Hagemann, Hans

AU - Fröhlich, Johannes

AU - Lumpi, Daniel

PY - 2015

Y1 - 2015

N2 - A rational molecular design strategy for carbazole-oxadiazole based bipolar host materials was developed to improve the device efficiency of blue phosphorescent organic light-emitting diodes (PHOLED). Steric effects of strategically placed methyl groups led to an increase of triplet energies (o-2MPCzPOXD: 2.66 eV and o-3MPCzPOXD: 2.73 eV versus the initial host material o-PczPOXD: 2.62 eV) while less pronouncedly affecting singlet energies and, therefore, retaining low driving voltages, high power efficiencies and remarkably low efficiency roll-offs in PHOLEDs. The maximum quantum efficiencies (EQE) for blue devices (FIrpic) were significantly raised for o-2MPCzPOXD (13.6%) and o-3MPCzPOXD (11.5%) versus o-PCzPOXD (9.0%) although yielding comparable values for green devices (Ir(ppy)3; 12.9% and 15.4% versus 13.2%). Supported by theoretical calculations a structure-property relationship was established from photo-physical properties, PHOLED performance measurements and structural characterization from single crystal data.

AB - A rational molecular design strategy for carbazole-oxadiazole based bipolar host materials was developed to improve the device efficiency of blue phosphorescent organic light-emitting diodes (PHOLED). Steric effects of strategically placed methyl groups led to an increase of triplet energies (o-2MPCzPOXD: 2.66 eV and o-3MPCzPOXD: 2.73 eV versus the initial host material o-PczPOXD: 2.62 eV) while less pronouncedly affecting singlet energies and, therefore, retaining low driving voltages, high power efficiencies and remarkably low efficiency roll-offs in PHOLEDs. The maximum quantum efficiencies (EQE) for blue devices (FIrpic) were significantly raised for o-2MPCzPOXD (13.6%) and o-3MPCzPOXD (11.5%) versus o-PCzPOXD (9.0%) although yielding comparable values for green devices (Ir(ppy)3; 12.9% and 15.4% versus 13.2%). Supported by theoretical calculations a structure-property relationship was established from photo-physical properties, PHOLED performance measurements and structural characterization from single crystal data.

KW - High triplet energy

KW - Low efficiency roll-off

KW - PHOLED

KW - Sterically induced torsion

KW - Structure-property relationship

UR - https://www.scopus.com/pages/publications/84937107579

U2 - 10.1016/j.orgel.2014.11.027

DO - 10.1016/j.orgel.2014.11.027

M3 - 文章

AN - SCOPUS:84937107579

SN - 1566-1199

VL - 17

SP - 216

EP - 228

JO - Organic Electronics

JF - Organic Electronics

IS - 1

ER -

Controlling singlet-triplet splitting in carbazole-oxadiazole based bipolar phosphorescent host materials

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Keywords

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