866100-16-5Relevant academic research and scientific papers
Influence of the auxiliary acceptor and π-bridge in carbazole dyes on photovoltaic properties
Liu, Yang,He, Ji,Han, Liang,Gao, Jianrong
, p. 283 - 292 (2017)
Six N-dimethylfluorenylcarbazole dyes have been synthesized based on benzene, furan and thiophene π-bridge with or without benzothiadiazole auxiliary acceptor. Their photophysical properties and photovoltaic performance are investigated systematically based on the incorporation of benzothiadiazole and the variety of π-bridges. The presence of benzothiadiazole broadens the absorption spectra and favors the light-harvesting abilities, which benefits better IPCE spectra and accordingly improved JSC. In addition, benzothiadiazole plays a role on the effects of π-bridge on the photoelectrical conversion efficiency. Dye bearing thiophene bridge achieves optimal photovoltaic performance 4.14% among those carbazole dyes without benzothiadiazole while when with benzothiadiazole dye bearing furan bridge exhibits the best cell efficiency 4.96% under AM 1.5G condition (N719 dye's 6.57% under the same condition).
A new N-fluorenyl carbazole host material: Synthesis, physical properties and applications for highly efficient phosphorescent organic light emitting diodes
Shin, Min-Gi,Thangaraju,Kim, Seul-Ong,Park, Jong-Won,Kim, Yun-Hi,Kwon, Soon-Ki
, p. 785 - 793 (2011)
A new N-fluorenyl carbazole material, 9,9′-bis-(9,9-dimethyl-9H- fluoren-2-yl)-9H,9′H-[3,3′]bicarbazolyl (BDFC), was synthesized by bromination, Ullmann and Yamamoto coupling reactions and confirmed using various spectroscopic studies. Thermogravimetric analysis and differential scanning calorimetry studies show the thermal stability (ΔT5%) of 494.7 °C with high glass transition temperature (Tg) of 177.8 °C. The photophysical and electrochemical studies of BDFC show the photoluminescence at 408 nm and a band gap of 3.01 eV with higher triplet energy of 2.72 eV. The phosphorescent organic light emitting diode using BDFC as host, ITO/di-[4-(N,N-ditolyl-amino)-phenyl]cyclohexane (TAPC)/host: fac-tris(2-phenylpyridine)-iridium [Ir(ppy)3] (5%)/1,3,5-tris(m- pyrid-3-yl-phenyl)benzene (TmPyPB)/LiF/Al, shows the effective confinement of triplet excitons and efficient energy transfer to the guest emitter in the emissive layer, resulted in the higher device efficiencies of 56.3 cd/A, 18.1% and 21.3 lm/W compared with that (48.1 cd/A, 15.3% and 16.3 lm/W) of device based on (4,4′-N,N′-dicarbazole)biphenyl (CBP) as host. The results show that the new host material BDFC could be useful for the efficient organic light emitting diodes.
