Improved Performance of Organic Light-Emitting Field-Effect Transistors by Interfacial Modification of Hole-Transport Layer/Emission Layer: Incorporating Organic Heterojunctions

2016 ◽  
Vol 8 (22) ◽  
pp. 14063-14070 ◽  
Author(s):  
Li Song ◽  
Yongsheng Hu ◽  
Nan Zhang ◽  
Yantao Li ◽  
Jie Lin ◽  
...  
Keyword(s):  
Field Effect Transistors ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Emission Layer ◽  
Light Emitting ◽  
Organic Light ◽  
Interfacial Modification ◽  
Improved Performance ◽  
Organic Heterojunctions

Layer Cross-Fading at Organic/Organic Interfaces in OVPD-Processed Red Phosphorescent Organic Light Emitting Diodes as a New Concept to Increase Current and Luminous Efficacy

2009 ◽  
Vol 1154 ◽  
Author(s):  
Florian Lindla ◽  
Manuel Boesing ◽  
Christoph Zimmermann ◽  
Frank Jessen ◽  
Philipp van Gemmern ◽  
...  
Keyword(s):  
Growth Rate ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Organic Layer ◽  
Driving Voltage ◽  
Emission Layer ◽  
Luminous Efficacy ◽  
Light Emitting ◽  
Organic Light

AbstractThe current and luminous efficacy of a red phosphorescent organic light emitting diode (OLED) with sharp interfaces between each of the organic layers can be increased from 18.8 cd/A and 14.1 lm/W (at 1,000 cd/m2) to 36.5 cd/A (+94%, 18% EQE) and 33.7 lm/W (+139%) by the introduction of a layer cross-fading zone at the hole transport layer (HTL) to emission layer (EL) interface. Layer cross-fading describes a procedure of linearly decreasing the fraction in growth rate of an organic layer during deposition over a certain thickness while simultaneously increasing the fraction in growth rate of the following layer. For OLED processing and layer cross-fading organic vapor phase deposition (OVPD) is used. The typical observation of a roll-off in current efficacy of phosphorescent OLED to higher luminance can be reduced significantly. An interpenetrating network of a prevailing hole and a prevailing electron conducting material is created in the cross-fading zone. This broadens the recombination zone and furthermore lowers the driving voltage. The concept of layer cross-fading to increase the efficacies is suggested to be useful in multi-colored OLED stacks as well.

El Behavior of Stylyl Compounds with Benzoxazole and Benzothiazole for Organic Light-Emitting-Diode

1999 ◽  
Vol 561 ◽  
Author(s):  
Koichi Yamashita ◽  
Kaname Imaizumi ◽  
Tatsuo Mori ◽  
Teruyoshi Mizutani ◽  
Hiroshi Miyazaki
Keyword(s):  
Applied Voltage ◽  
Light Emitting Diode ◽  
Green Light ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Emission Layer ◽  
Light Emitting ◽  
Organic Light ◽  
Current Densities

ABSTRACTWe studied the EL behaviors of benzoheterocyclic derivatives as emitting and hole transport layers for organic light-emitting-diodes (OLEDs). First, we studied the benzoheterocyclic derivatives having stylyl group, triphenylamine group and benzoxazole or benzothiazole group as an emission layer. These devices emitted a blue-green light. The current densities of the OLED having these benzoheterocyclic derivatives as an emission layer were higher than that of the Alq3 OLED at same applied voltage. However, these devices did not have a high EL efficiency (maximum 0.1 lm/W). From these results, in these benzoheterocyclic derivatives having a triphenylamine group, we thought that holes could flow out from hole transport to cathode. We newly synthesized dimer-type benzoheterocyclic derivatives without a triphenylamine group, which have benzoheterocycle at both sides. The current densities of the OLEDs having dimer-type benzoheterocyclic derivatives was more strongly suppressed than that of the OLEDs having benzoheterocyclic derivatives with a triphenylamine group at same applied voltage, but the EL efficiency could not be improved by dimerization and eliminating of a triphenyldiamine group obtained. Next, we studied the TPD derivatives having benzoxazole, benzothiazole and stylyl groups as hole transport layer. In new TPD derivatives, the EL efficiency the OLEDs having the TPD derivatives with stylyl groups was the best efficiency of all. The EL efficiency of ITO/a TPD derivative with stylyl groups/Alq3/AlLi is 1. 1 lm/W (max. luminance 12000cd/m2).

scholarly journals Improved performance of perovskite light-emitting diodes with a NaCl doped PEDOT:PSS hole transport layer

2021 ◽  
Author(s):  
Xiaokun Huang ◽  
Rainer Bäuerle ◽  
Felix Scherz ◽  
Jean-Nicolas Tisserant ◽  
Wolfgang Kowalsky ◽  
...  
Keyword(s):  
Alkali Halide ◽  
Light Emitting Diodes ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Light Emitting ◽  
Improved Performance

We demonstrate a simple and effective way to enhance the performance of perovskite light-emitting diodes (PeLEDs) by utilizing an alkali halide doped PEDOT:PSS as the hole transport layer (HTL). The...

scholarly journals Study of Nanostructured Polymeric Composites Used for Organic Light Emitting Diodes and Organic Solar Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Nguyen Nang Dinh ◽  
Do Ngoc Chung ◽  
Tran Thi Thao ◽  
David Hui
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Light Emitting Diodes ◽  
Hole Transport ◽  
Organic Light Emitting Diodes ◽  
Transport Layer ◽  
Nanocomposite Films ◽  
Hole Transport Layer ◽  
Light Emitting ◽  
Organic Light

Polymeric nanocomposite films from PEDOT and MEH-PPV embedded with surface modified TiO2nanoparticles for the hole transport layer and emission layer were prepared, respectively, for organic emitting diodes (OLEDs). The composite of MEH-PPV+nc-TiO2was used for organic solar cells (OSCs). The characterization of these nanocomposites and devices showed that electrical (I-Vcharacteristics) and spectroscopic (photoluminescent) properties of conjugate polymers were enhanced by the incorporation of nc-TiO2in the polymers. The organic light emitting diodes made from the nanocomposite films would exhibit a larger photonic efficiency and a longer lasting life. For the organic solar cells made from MEH-PPV+nc-TiO2composite, a fill factor reached a value of about 0.34. Under illumination by light with a power density of 50 mW/cm2, the photoelectrical conversion efficiency was about 0.15% corresponding to an open circuit voltageVoc= 0.126 V and a shortcut circuit current densityJsc= 1.18 mA/cm2.

Study of nanostructured polymeric composites used for organic light emitting diodes and organic solar cells

2012 ◽  
Vol 9 (5) ◽  
pp. 399-406
Author(s):  
Do Chung ◽  
Nguyen Dinh ◽  
Tran Thao ◽  
Nguyen Nam ◽  
Tran Trung ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Light Emitting Diodes ◽  
Hole Transport ◽  
Organic Light Emitting Diodes ◽  
Transport Layer ◽  
Nanocomposite Films ◽  
Hole Transport Layer ◽  
Light Emitting ◽  
Organic Light

Polymeric nanocomposite films from PEDOT and MEH-PPV embedded with surface modified TiO2 nanoparticles were prepared, respectively for the hole transport layer (HTL) and emission layer (EL) in Organic Light Emitting Diodes (OLED). The composite of MEH-PPV + nc-TiO2 was used for Organic Solar Cells (OCS). The results from the characterization of the properties of the nanocomposites and devices showed that electrical (I-V characteristics) and spectroscopic (photoluminescent) properties of the conjugate polymers were enhanced due to the incorporation of nc-TiO2 in the polymers. The OLEDs made from the nanocomposite films would exhibit a larger photonic efficiency and a longer lasting life. For the OSC made from MEH-PPV + nc-TiO2 composite, the fill factor (FF) reached a value as high as 0.34. Under illumination of light with a power density of 50 mW/cm2, the photoelectrical conversion efficiency (PEC) was found to be of 0.15% corresponding to an open circuit voltage VOC = 1.15 V and a short-cut circuit current density JSC = 0.125 mA/cm2.

The Study of Hole Injection in OLEDs with Ultra-Thin Sol-Gel TiO2 Layer

2011 ◽  
Vol 189-193 ◽  
pp. 42-46
Author(s):  
You Wang Hu ◽  
Xiao Yan Sun ◽  
Jian Duan
Keyword(s):  
Sol Gel ◽  
Hole Transport ◽  
Organic Light Emitting Diodes ◽  
Transport Layer ◽  
Hole Injection ◽  
Hole Transport Layer ◽  
Carrier Injection ◽  
Light Emitting ◽  
Organic Light ◽  
Pre Treatment

Organic light-emitting diodes (OLEDs) with inserting an ultrathin sol–gel titanium oxide (TiO2) buffer layer between the ITO anode and hole transport layer (HTL) were fabricated. The carrier injection and the device efficiency were affected by surface morphology of TiO2, which was changed by different plasma pre-treatment of ITO. Treated by CF4 plasma, the TiO2 layer is the smoothest, and treated by H2 plasma it is like island. The TiO2 layer like island is favor of carrier injection from the anode, which was attributed to the point discharged.

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