Balancing carrier injection/transport through CN-modification on classical hole-transport host for enhanced performance in phosphorescent OLEDs

Yeting Tao; Yuying Wu; Yaotian Zhang; Jingsheng Wang; Youtian Tao

doi:10.1016/j.sse.2025.109075

Balancing carrier injection/transport through CN-modification on classical hole-transport host for enhanced performance in phosphorescent OLEDs

Yeting Tao, Yuying Wu, Yaotian Zhang, Jingsheng Wang, Youtian Tao

SCHOOL OF FLEXIBLE ELECTRONICS(FUTURE TECHNOLOGIES)|INSTITUTE OF ADVANCED MATERIALS(IAM)

Nanjing Tech University

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

Abstract

Two bipolar host materials, TCTA-3CN and TCTA-4CN, are developed by incorporating strong electron-withdrawing cyano groups at the 3- or 4-position of carbazole in classical hole-transport tris(4-carbazoyl-9-ylphenyl)amine (TCTA). Their HOMO/LUMO energy levels were significantly reduced to −5.56/−2.32 eV and −5.60/−2.48 eV, respectively, compared to −5.19/−1.92 eV for TCTA. This CN-modification results in a markedly improved carrier balance, as evidenced by a reduction in the hole/electron current ratio from >16,000 for TCTA to ∼45 for both TCTA-3CN and TCTA-4CN in the corresponding single-carrier devices at 4 V. When utilized as host materials for (ppy)₂Ir(acac) based devices, a synergistic enhancement in luminescence and efficiency was observed.

Original language	English
Article number	109075
Journal	Solid-State Electronics
Volume	225
DOIs	https://doi.org/10.1016/j.sse.2025.109075
State	Published - Apr 2025

Keywords

Bipolar transport
Host
Luminescence
Organic light-emitting diodes
Phosphorescence

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10.1016/j.sse.2025.109075

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Tao, Y., Wu, Y., Zhang, Y., Wang, J., & Tao, Y. (2025). Balancing carrier injection/transport through CN-modification on classical hole-transport host for enhanced performance in phosphorescent OLEDs. Solid-State Electronics, 225, Article 109075. https://doi.org/10.1016/j.sse.2025.109075

@article{a0c7b7911f53498c92872aab5e149956,

title = "Balancing carrier injection/transport through CN-modification on classical hole-transport host for enhanced performance in phosphorescent OLEDs",

abstract = "Two bipolar host materials, TCTA-3CN and TCTA-4CN, are developed by incorporating strong electron-withdrawing cyano groups at the 3- or 4-position of carbazole in classical hole-transport tris(4-carbazoyl-9-ylphenyl)amine (TCTA). Their HOMO/LUMO energy levels were significantly reduced to −5.56/−2.32 eV and −5.60/−2.48 eV, respectively, compared to −5.19/−1.92 eV for TCTA. This CN-modification results in a markedly improved carrier balance, as evidenced by a reduction in the hole/electron current ratio from >16,000 for TCTA to ∼45 for both TCTA-3CN and TCTA-4CN in the corresponding single-carrier devices at 4 V. When utilized as host materials for (ppy)2Ir(acac) based devices, a synergistic enhancement in luminescence and efficiency was observed.",

keywords = "Bipolar transport, Host, Luminescence, Organic light-emitting diodes, Phosphorescence",

author = "Yeting Tao and Yuying Wu and Yaotian Zhang and Jingsheng Wang and Youtian Tao",

note = "Publisher Copyright: {\textcopyright} 2025 Elsevier Ltd",

year = "2025",

month = apr,

doi = "10.1016/j.sse.2025.109075",

language = "英语",

volume = "225",

journal = "Solid-State Electronics",

issn = "0038-1101",

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TY - JOUR

T1 - Balancing carrier injection/transport through CN-modification on classical hole-transport host for enhanced performance in phosphorescent OLEDs

AU - Tao, Yeting

AU - Wu, Yuying

AU - Zhang, Yaotian

AU - Wang, Jingsheng

AU - Tao, Youtian

PY - 2025/4

Y1 - 2025/4

N2 - Two bipolar host materials, TCTA-3CN and TCTA-4CN, are developed by incorporating strong electron-withdrawing cyano groups at the 3- or 4-position of carbazole in classical hole-transport tris(4-carbazoyl-9-ylphenyl)amine (TCTA). Their HOMO/LUMO energy levels were significantly reduced to −5.56/−2.32 eV and −5.60/−2.48 eV, respectively, compared to −5.19/−1.92 eV for TCTA. This CN-modification results in a markedly improved carrier balance, as evidenced by a reduction in the hole/electron current ratio from >16,000 for TCTA to ∼45 for both TCTA-3CN and TCTA-4CN in the corresponding single-carrier devices at 4 V. When utilized as host materials for (ppy)2Ir(acac) based devices, a synergistic enhancement in luminescence and efficiency was observed.

AB - Two bipolar host materials, TCTA-3CN and TCTA-4CN, are developed by incorporating strong electron-withdrawing cyano groups at the 3- or 4-position of carbazole in classical hole-transport tris(4-carbazoyl-9-ylphenyl)amine (TCTA). Their HOMO/LUMO energy levels were significantly reduced to −5.56/−2.32 eV and −5.60/−2.48 eV, respectively, compared to −5.19/−1.92 eV for TCTA. This CN-modification results in a markedly improved carrier balance, as evidenced by a reduction in the hole/electron current ratio from >16,000 for TCTA to ∼45 for both TCTA-3CN and TCTA-4CN in the corresponding single-carrier devices at 4 V. When utilized as host materials for (ppy)2Ir(acac) based devices, a synergistic enhancement in luminescence and efficiency was observed.

KW - Bipolar transport

KW - Host

KW - Luminescence

KW - Organic light-emitting diodes

KW - Phosphorescence

UR - http://www.scopus.com/inward/record.url?scp=85216119411&partnerID=8YFLogxK

U2 - 10.1016/j.sse.2025.109075

DO - 10.1016/j.sse.2025.109075

M3 - 文章

AN - SCOPUS:85216119411

SN - 0038-1101

VL - 225

JO - Solid-State Electronics

JF - Solid-State Electronics

M1 - 109075

ER -

Balancing carrier injection/transport through CN-modification on classical hole-transport host for enhanced performance in phosphorescent OLEDs

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Keywords

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