scholarly journals Partitioning pixel of organic light-emitting devices with center-hollowed microlens-array films for efficiency enhancement

2010 ◽  
Vol 18 (18) ◽  
pp. 18685 ◽  
Author(s):  
Kuan-Yu Chen ◽  
Yu-Ting Hsiao ◽  
Hoang Yan Lin ◽  
Mao-Kuo Wei ◽  
Jiun-Haw Lee
Keyword(s):  
Microlens Array ◽  
Efficiency Enhancement ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Organic Light Emitting Devices

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.

scholarly journals Efficiency enhancement of flexible organic light-emitting devices by using antireflection nanopillars

2011 ◽  
Vol 19 (S3) ◽  
pp. A295 ◽  
Author(s):  
Yu-Hsuan Ho ◽  
Chung-Chun Liu ◽  
Shun-Wei Liu ◽  
Hsun Liang ◽  
Chih-Wei Chu ◽  
...  
Keyword(s):  
Efficiency Enhancement ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Organic Light Emitting Devices

Microlens Array Fabrication by 3D Diffuser Lithography for Light Enhancement of Organic Light-Emitting Devices

2014 ◽  
Vol 625 ◽  
pp. 430-436
Author(s):  
Hung Yi Lin ◽  
Yong Shan Sun ◽  
Shih Liang Chen ◽  
Mao Kuo Wei
Keyword(s):  
Fill Factor ◽  
Microlens Array ◽  
Microlens Arrays ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Circular Holes ◽  
Organic Light Emitting Devices ◽  
Pdms Molding ◽  
Array Fabrication

Microlens arrays have been fabricated by 3D diffuser lithography in this study. The method mainly adopts two kinds of diffuser films with different transmittances and hazes, integrated by photolithography, polydimethylsiloxane (PDMS) molding and UV forming techniques, to get microlens arrays with different parameters and geometries. The features, such as height, geometry and fill factor of microlens arrays, are controlled by photolithography, using a photomask with circular holes and different exposure doses. The microlens arrays can also be duplicated and transferred to the surface of flexible polyethylene terephthalate (PET) substrate through PDMS molding and UV forming processes. Finally, the outcoupling efficiency of microlens arrays attached to organic light-emitting devices (OLEDs) can be measured and analyzed. More than 60% enhancement of luminous current efficiency can be obtained in 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.

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