Efficiency Enhancement of Tandem Organic Light-Emitting Devices Fabricated Utilizing an 1,4,5,8,9,11-Hexaazatriphenylene-Hexacarbonitrile Charge-Generation Layer

2015 ◽  
Vol 15 (10) ◽  
pp. 7717-7721
Author(s):  
Young Pyo Jeon ◽  
Tae Whan Kim
Keyword(s):  
Current Density ◽  
Efficiency Enhancement ◽  
Charge Generation ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Maximum Current ◽  
Organic Light Emitting Devices ◽  
Generation Mechanisms ◽  
A Charge

The electrical and the optical properties of tandem organic light-emitting devices (OLEDs) with stacked electroluminescence units were investigated to clarify the charge-generation mechanisms due to the existence of a charge-generation layer (CGL). The current density of the current limited devices with an 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN) CGL was 35% higher than that of devices with a tungsten-oxide (WO3) CGL. The maximum current density of the current limited devices with a HAT-CN CGL was as high as 259 mA/cm2. The brightness of the tandem OLEDs with a HAT-CN CGL was 15% higher than that of the tandem OLEDs with a WO3 CGL due to an increase in the current density. The charge-generation mechanisms of tandem OLEDs with a CGL were described on the basis of the experimental results.

Efficiency Enhancement of Tandem Organic Light-Emitting Devices Fabricated Utilizing an Organic BEDT-TTF and HAT-CN Charge Generation Layer

2015 ◽  
Vol 15 (10) ◽  
pp. 8070-8074
Author(s):  
Dae Hun Kim ◽  
Tae Whan Kim
Keyword(s):  
Current Efficiency ◽  
Operating Voltage ◽  
Efficiency Enhancement ◽  
Charge Generation ◽  
Electrical And Optical Properties ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Highest Occupied Molecular Orbital ◽  
Organic Light Emitting Devices

The electrical and optical properties of tandem organic light-emitting devices (OLEDs) fabricated utilizing an organic bis(ethylenedithio)-tetrathiafulvalene (BEDT-TTF) and 1,4,5,8,9,11- hexaazatriphenylenehexacarbonitrile (HAT-CN) charge generation layer (CGL) were investigated to enhance their efficiency. While the operating voltage of the tandem OLEDs with a BEDT-TTF and HAT-CN CGL at 50 mA/cm2 was 11.2 V lower than that of the tandem OLEDs without a CGL, the current efficiency of the tandem OLEDs with a BEDT-TTF and a HAT-CN CGL at 50 mA/cm2 was 0.8 cd/A higher than that of the tandem OLEDs without a CGL. An increase in the current efficiency and a decrease in the operating voltage of the tandem OLEDs with a BEDT-TTF and an HAT-CN CGL were attributed to the enhancement of the electron injection due to its existence in the highest occupied molecular orbital level of the BEDT-TTF between the HAT-CN and the tris-(8- hydroxyquinoline)aluminum layer.

White Stacked Electrophosphorescent Organic Light-Emitting Devices Employing MoO3 as a Charge-Generation Layer

2006 ◽  
Vol 18 (3) ◽  
pp. 339-342 ◽  
Author(s):  
H. Kanno ◽  
R. J. Holmes ◽  
Y. Sun ◽  
S. Kena-Cohen ◽  
S. R. Forrest
Keyword(s):  
Charge Generation ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Organic Light Emitting Devices ◽  
A Charge

Inverted organic light-emitting devices using a charge-generation unit as an electron injector

2020 ◽  
Vol 76 ◽  
pp. 105445
Author(s):  
Ruiqing Li ◽  
Jiong Wang ◽  
Yue Qin ◽  
Chenyang Liu ◽  
Yuzhu Wang ◽  
...  
Keyword(s):  
Charge Generation ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Electron Injector ◽  
Organic Light ◽  
Organic Light Emitting Devices ◽  
A Charge ◽  
Generation Unit

Efficiency Enhancement of Organic Light-Emitting Devices Fabricated Using a 1,4,5,8,9,11-Hexaazatriphenylene Hexacarbonitrile Silver Electrode

2015 ◽  
Vol 15 (10) ◽  
pp. 7791-7794
Author(s):  
Y. P. Jeon ◽  
Y. H. Choi ◽  
T.W. Kim
Keyword(s):  
Current Density ◽  
Transparent Electrode ◽  
Efficiency Enhancement ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Organic Light Emitting Devices ◽  
Micro Cavity ◽  
20 Nm ◽  
Cavity Effect

A 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HAT-CN)/Ag/HAT-CN transparent electrode for organic light-emitting devices (OLEDs) was investigated. The current density of OLEDs was enhanced with an increase in the Ag layer thickness of a HAT-CN/Ag/HAT-CN anode. While the luminance of the OLEDs with a HAT-CN/Ag/HAT-CN anode slightly decreased with increasing thickness of the upper HAT-CN layer, the current efficiency of the OLEDs with thicknesses for the Ag layer of 20 nm and for the upper HAT-CN layer of 100 nm was almost two times higher than that of OLEDs with an ITO anode. Electroluminescence spectra of the OLEDs with a HAT-CN/Ag/HAT-CN anode were shifted due to the micro-cavity effect in the stacked anode, which was confirmed by the transmittance spectra.

Efficiency Enhancement Mechanisms in Tandem Organic Light-Emitting Devices Fabricated Utilizing a Mixed LCV: HAT-CN Layer Embedded Into a Charge Generation Layer

2015 ◽  
Vol 15 (10) ◽  
pp. 8191-8194
Author(s):  
Eun Im Koh ◽  
Dae Hun Kim ◽  
Tae Whan Kim
Keyword(s):  
Current Efficiency ◽  
Mixed Layer ◽  
Operating Voltage ◽  
Charge Generation ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
The Matrix ◽  
Organic Light Emitting Devices ◽  
A Charge

Tandem organic light-emitting devices (OLEDs) with a mixed organic n-type 4,4′,4″-methylidynetris (n,n-dimethylaniline) and organic p-type 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile layer embedded into a charge generation layer (CGL) were fabricated to enhance their current efficiency. The operating voltage of the tandem OLEDs with a mixed layer at 10 mA/cm2 was 1 V lower than that of the tandem OLEDs without a mixed layer due to the electrons generated from the mixed layer. The matrix-assisted laser desorption-ionization-time-of-flight mass spectrometer spectra clarified the charge generation behaviors of the mixed layer into the CGL. The current efficiency of the tandem OLEDs with a mixed layer at 10 mA/cm2 was 48.2 cd/A, which was much larger than that without a mixed layer. The increase in the current efficiency for the tandem OLEDs was attributed to the enhancement of the electron injection efficiency in a CGL resulting from the insertion of the mixed layer.

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