NDLI: Carbazole oligomers revisited: new additions at the carbazole 1- and 8-positions

Content Provider	Royal Society of Chemistry (RSC)
Author	Huang, De-Kang Gong, Wen-Liang Ma, Dongge Shen, Yan Qiao, Xian-Feng Zhong, Fang Chen, Tao Fu, Qiang Aldred, Matthew. P. Zhu, Ming-Qiang
Copyright Year	2012
Abstract	In recent years low molecular weight carbazole-based materials have attracted much interest as hole-transporting and host materials for organic light emitting diode (OLED) applications. Herein we report the tri- and tetra-bromination of carbazole and the subsequent synthesis of novel carbazole oligomers substituted at the 1- and 8-positions. The oligomer series range from mono-carbazole (Cz-1) to quinque-carbazole (Cz-5) and we have carried out a comparative study of their thermal, optical, electrochemical and optoelectronic properties. The glass transition temperature increases as the carbazole core is enlarged (0 °C to 54 °C) and all oligomers exhibit excellent thermal stability with high thermal decomposition temperatures in the range of 442 °C to 494 °C. From optical data and Raman spectroscopy we observe negligible changes in the effective conjugation length as the number of peripheral carbazole units increases. However, the oxidation potential decreases as the number of carbazole units increase, in which Cz-5 exhibits the highest HOMO level (−5.19 eV) compared to other carbazole oligomers in the series. All carbazole materials emit deep blue photoluminescence ranging from 416 to 432 nm in the solid-state. Finally, electrophosphorescence was demonstrated from solution processable guest-host organic light- emitting diodes (OLEDs) fabricated using Cz(2–5) as the host materials with device configuration ITO/PEDOT/Cz1–5 : 10% Ir(mppy)3/TPBi/LiF/Al. The device efficiency decreases from Cz-3 to Cz-5. The best OLED device that incorporates Cz-3 as the host exhibits a turn-on voltage of 2.8 V, maximum brightness of 2310 cd m−2, maximum power efficiency of 33.6 lm W−1, maximum current efficiency 35.5 cd A−1 and EQE of 10.6%.
Starting Page	10821
Ending Page	10828
Page Count	8
File Format	HTM / HTML PDF
ISSN	20462069
Volume Number	2
Issue Number	29
Journal	RSC Advances
DOI	10.1039/c2ra21657d
Language	English
Publisher	Royal Society of Chemistry
Access Restriction	Open
Subject Keyword	Optoelectronics HOMO\/LUMO Poly(3,4-ethylenedioxythiophene) Photoluminescence Electronvolt Oligomer Raman spectroscopy Carbazole Glass transition EQE Electrochemistry OLED Raman Light-emitting diode
Content Type	Text
Resource Type	Article
Subject	Chemistry Chemical Engineering

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Light-emitting poly(N-naphthyl-2,7-carbazole)

Carbazole functionalized new bipolar ligand for monochromatic red light-emitting europium(iii) complex: combined experimental and theoretical study

The first aggregation-induced emission fluorophore as a solution processed host material in hybrid white organic light-emitting diodes

HOMO energy level regulation of novel conjugated copolymers for polymer solar cells

Third-order nonlinear optical properties of 3,4-ethylenedioxythiophene copolymers with chalcogenadiazole acceptors

Manipulation of electron deficiency of δ-carboline derivatives as bipolar hosts for blue phosphorescent organic light-emitting diodes with high efficiency at 1000 cd m⁻²

A dithienyl benzotriazole-based poly(2,7-carbazole) for field-effect transistors and efficient light-emitting diodes

Synthesis and photovoltaic performance of donor–acceptor copolymers based on thieno[3,2-b]quinoxaline

Synthesis and properties of benzo[c]-, pyrrolo[3,4-c]-, and thieno[3,4-c]-pyrrole-4,6-dione copolymers

Carbazole oligomers revisited: new additions at the carbazole 1- and 8-positions

Similar Documents

Light-emitting poly(N-naphthyl-2,7-carbazole)

Carbazole functionalized new bipolar ligand for monochromatic red light-emitting europium(iii) complex: combined experimental and theoretical study

The first aggregation-induced emission fluorophore as a solution processed host material in hybrid white organic light-emitting diodes

HOMO energy level regulation of novel conjugated copolymers for polymer solar cells

Third-order nonlinear optical properties of 3,4-ethylenedioxythiophene copolymers with chalcogenadiazole acceptors

Manipulation of electron deficiency of δ-carboline derivatives as bipolar hosts for blue phosphorescent organic light-emitting diodes with high efficiency at 1000 cd m−2

A dithienyl benzotriazole-based poly(2,7-carbazole) for field-effect transistors and efficient light-emitting diodes

Synthesis and photovoltaic performance of donor–acceptor copolymers based on thieno[3,2-b]quinoxaline

Synthesis and properties of benzo[c]-, pyrrolo[3,4-c]-, and thieno[3,4-c]-pyrrole-4,6-dione copolymers

Carbazole oligomers revisited: new additions at the carbazole 1- and 8-positions

Manipulation of electron deficiency of δ-carboline derivatives as bipolar hosts for blue phosphorescent organic light-emitting diodes with high efficiency at 1000 cd m⁻²