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Both Luminous Efficiency and Lifetime Enhancement in Blue Fluorescence OLEDs by Modifying Molecular Structure of Hole Transporting Material

Published online by Cambridge University Press:  14 January 2011

Yoonhyun Kwak
Affiliation:
OLED Precede Technology Team, Samsung Mobile Display Co., Ltd., Gyunggi-Do 446-711, Korea
Sun-Young Lee
Affiliation:
OLED Precede Technology Team, Samsung Mobile Display Co., Ltd., Gyunggi-Do 446-711, Korea
Hye-In Jeong
Affiliation:
OLED Precede Technology Team, Samsung Mobile Display Co., Ltd., Gyunggi-Do 446-711, Korea
Dae-Yup Shin
Affiliation:
OLED Development Department, Samsung Mobile Display Co., Ltd., Gyunggi-Do 446-711, Korea
Young-Woo Song
Affiliation:
OLED Precede Technology Team, Samsung Mobile Display Co., Ltd., Gyunggi-Do 446-711, Korea
Jong Hyuk Lee
Affiliation:
OLED Precede Technology Team, Samsung Mobile Display Co., Ltd., Gyunggi-Do 446-711, Korea
Sung Chul Kim
Affiliation:
OLED Development Department, Samsung Mobile Display Co., Ltd., Gyunggi-Do 446-711, Korea
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Abstract

Both luminous efficiency and lifetime in blue fluorescence organic light emitting devices (OLEDs) have been improved by modified HTMs with higher LUMO energy levels. The LUMO energy levels of HTM were increased by modifying substituent in HTM molecules. Two HTMs containing ortho and meta biphenyl substituent and one HTM containing thiophene substituent were synthesized via palladium catalyzed amine coupling reactions to compare with a para biphenyl substituent HTM-1 as a standard molecule. According to TDDFT calculations, these three modified HTMs showed 0.05-0.15 eV higher LUMO energy levels compared to the para biphenyl substituent HTM-1. The luminous efficiency and the lifetime (LT90) of OLEDs using HTM-2 at 500 cd/m2 have been enhanced up to 20 % and 52 %, respectively, compared to the standard device using HTM-1.

Type
Research Article
Copyright
Copyright © Materials Research Society 2011

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References

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