Investigation of hole-injection in α-NPD using capacitance and impedance spectroscopy techniques with F4TCNQ as hole-injection layer: Initial studies

Fernandes, Jean Maria; Kiran, M. Raveendra; Ulla, Hidayath; Satyanarayan, M. N.; Umesh, G.

doi:10.1016/j.spmi.2014.10.026

Cited by 11 publications

(4 citation statements)

References 37 publications

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“…F 4 TCNQ (2,3,5,6‐Tetrafluoro‐7,7,8,8‐tetracyano quinodimethane) was chosen as hole injection layer (HIL) as it efficiently injects holes from the ITO anode to hole‐transport layer (HTL). An optimized thickness of F 4 TCNQ was used for better hole injection as reported earlier α‐NPD (4,4’‐bis[N‐(1‐naphthyl)‐N‐phenyl‐l‐amino]‐biphenyl) was chosen as the (HTL) because of its high HOMO energy, in addition, considering the energy levels of materials used in the OLEDs, α‐NPD with a higher LUMO level also plays a role of an effective electron‐blocking material (EBL). By using BCP (bathocuproine) as hole‐blocking material (HBL), the reductant holes are confined in the emitting layer which didn't recombine with the electrons in the emitting zone .…”

Section: Resultsmentioning

confidence: 99%

Star‐Shaped Phenanthroimidazole‐Triphenylamine‐Based Yellow Organic Emitter for Organic Light Emitting Diodes

et al. 2017

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In this work, new star-shaped conjugated organic emitter, namely tris(4-(1-(9,9-diethyl-9H-fluoren-2-yl)-1H-phenanthro [9,10-d]imidazol-2-yl)phenyl)amine (PIFTPA) with donor-p-acceptor (D-p-A) structure, was designed and synthesized by combining three fluoren-phenanthroimidazole arms into a triphenylamine core and characterized using 1 H, 13 C NMR and mass spectrometry. The detailed photophysical, thermal, electrochemical and electroluminescence properties were systematically studied. The organic emitter exhibits high glass transition temperature (230 8C) and high thermal stability with decomposition temperature. Electrochemical analysis reveals that the emitter has distinct oxidation and reduction behaviours. Furthermore, theoretical calculations (DFT) were performed to get a better understanding of the electronic structure. The OLEDs using this emitter as emissive material showed good device performance (6.45 cd/A, 4.39 lm/W, and 3.01%) with yellow emission and a low turn-on voltage (2.87 V). The results demonstrate that TPA integrated with phenthroimdazole plays an important role in the device performance.[a] J.

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Section: Resultsmentioning

confidence: 99%

Star‐Shaped Phenanthroimidazole‐Triphenylamine‐Based Yellow Organic Emitter for Organic Light Emitting Diodes

et al. 2017

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“…Here, F 4 TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) acts as a hole-injecting layer (HIL). An optimized thickness of F 4 TCNQ was used for better hole injection as reported previously . The device performance data are presented in Table .…”

Section: Resultsmentioning

confidence: 99%

“…With the inclusion of 4 nm of F 4 TCNQ layer (device III) there is an increase of efficiencies: 13.56 cd A –1 (η c ), 9.56 lm W –1 (η p ), and 5.34% (η ext ). This can be ascribed to the efficient injection of holes from the ITO anode to the hole transport layer α-NPD. − Furthermore, in device IV, with the use of BCP as a HBL, there is a further increase in the efficiencies. This increase in efficiencies may be due to the confining of redundant holes in the emitting layer which did not recombine with the electrons in the emitting zone .…”

Section: Resultsmentioning

confidence: 99%

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Pyrene–Oxadiazoles for Organic Light-Emitting Diodes: Triplet to Singlet Energy Transfer and Role of Hole-Injection/Hole-Blocking Materials

et al. 2015

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Three pyrene-oxadiazole derivatives were synthesized and characterized by optical, electrochemical, thermal, and theoretical investigations to obtain efficient multifunctional organic light emitting diode (OLED) materials. Synthesized molecules were used as emitters and electron transporters in three different device configurations, involving hole-injection/hole-blocking materials that showed good current and power efficiencies. To understand the underlying mechanisms involved in the application of these molecules as emitters and transporters, a detailed photophysical characterization of molecules 4-6 was carried out. The absorption, steady-state fluorescence, phosphorescence, fluorescence lifetime, and phosphorescence lifetime measurements were carried out. The high quantum yield and efficient reverse intersystem crossing leading to delayed fluorescence emission makes the molecule a good emitter, and the charge delocalization properties leading to excimer formation make them efficient electron transporters. Isoenergetic singlet and triplet states of the molecules make the reverse intersystem crossing feasible at room temperature even in the absence of thermal activation.

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New green emitters based on push-pull type pyrene substituted cyanopyridones: Design strategies and utilization in organic light-emitting diodes

Vishrutha

Ulla

et al. 2023

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Investigation of hole-injection in α-NPD using capacitance and impedance spectroscopy techniques with F4TCNQ as hole-injection layer: Initial studies

Cited by 11 publications

References 37 publications

Star‐Shaped Phenanthroimidazole‐Triphenylamine‐Based Yellow Organic Emitter for Organic Light Emitting Diodes

Star‐Shaped Phenanthroimidazole‐Triphenylamine‐Based Yellow Organic Emitter for Organic Light Emitting Diodes

Pyrene–Oxadiazoles for Organic Light-Emitting Diodes: Triplet to Singlet Energy Transfer and Role of Hole-Injection/Hole-Blocking Materials

New green emitters based on push-pull type pyrene substituted cyanopyridones: Design strategies and utilization in organic light-emitting diodes

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