Spatially-resolved electroluminescence of operating organic light-emitting diodes using conductive atomic force microscopy

2004 ◽  
Vol 85 (2) ◽  
pp. 344-346 ◽  
Author(s):  
L. S. C. Pingree ◽  
M. C. Hersam ◽  
M. M. Kern ◽  
B. J. Scott ◽  
T. J. Marks
Keyword(s):  
Atomic Force Microscopy ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Conductive Atomic Force Microscopy ◽  
Light Emitting ◽  
Force Microscopy ◽  
Spatially Resolved ◽  
Atomic Force ◽  
Organic Light

scholarly journals Slot-Die Coating of Double Polymer Layers for the Fabrication of Organic Light Emitting Diodes

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 53 ◽  
Author(s):  
Amruth C ◽  
Marco Colella ◽  
Jonathan Griffin ◽  
James Kingsley ◽  
Nicholas Scarratt ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Processing Parameters ◽  
Organic Light Emitting Diodes ◽  
Hole Injection ◽  
Light Emitting ◽  
Force Microscopy ◽  
Slot Die Coating ◽  
Atomic Force ◽  
Organic Light ◽  
Slot Die

This study presents the slot-die coating process of two layers of organic materials for the fabrication of organic light emitting diodes (OLEDs). Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), which is commonly used in OLEDs and in organic photovoltaic devices as the hole injection layer (HIL), has been deposited via slot-die coating. Uniform films of PEDOT:PSS were obtained after optimizing the slot-die processing parameters: substrate temperature, coating speed, and ink flow rate. The film quality was examined using optical microscopy, profilometry, and atomic force microscopy. Further, poly(9,9-dioctylfluorene) (F8) and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT), a well know polymer blend F8:F8BT, which is used as an emissive layer in OLEDs, has been slot-die coated. The optoelectronic properties of the slot-die coated F8:F8BT films were examined by means of photoluminescence (PL) and electroluminescence (EL) studies. The fabricated OLEDs, consisting of slot-die coated PEDOT:PSS and F8:F8BT films, were characterized to record the brightness and current efficiency.

Localized Current Injection and Submicron Organic Light-Emitting Device on a Pyramidal Atomic Force Microscopy Tip

Nano Letters ◽  
2007 ◽  
Vol 7 (12) ◽  
pp. 3645-3649 ◽  
Author(s):  
Yiying Zhao ◽  
Kwang H. An ◽  
Shuo Chen ◽  
Brendan O'Connor ◽  
Kevin P. Pipe ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Current Injection ◽  
Light Emitting ◽  
Force Microscopy ◽  
Atomic Force ◽  
Organic Light

scholarly journals Thiocyanate-Treated Perovskite-Nanocrystal-Based Light-Emitting Diodes with Insight in Efficiency Roll-Off

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 367 ◽  
Author(s):  
Fang Chen ◽  
Karunakara Moorthy Boopathi ◽  
Muhammad Imran ◽  
Simone Lauciello ◽  
Marco Salerno
Keyword(s):  
High Stability ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Ammonium Thiocyanate ◽  
Conductive Atomic Force Microscopy ◽  
Light Emitting ◽  
Force Microscopy ◽  
Atomic Force ◽  
Thiocyanate Solution ◽  
Green Led

Light emitting diodes (LED) based on halide perovskite nanocrystals (NC) have received widespread attention in recent years. In particular, LEDs based on CsPbBr3 NCs were the object of special interest. Here, we report for the first time green LED based on CsPbBr3 NCs treated with ammonium thiocyanate solution before purification with polar solvent. The champion device fabricated based on the treated CsPbBr3 NCs showed high efficiency and high stability during operation as well as during storage. A study on morphology and current distribution of NC films under applied voltages was carried out by conductive atomic force microscopy, giving a hint on efficiency roll-off. The current work provides a facile way to treat sensitive perovskite NCs and to fabricate perovskite NC-based LED with high stability. Moreover, the results shed new light on the relation between film morphology and device performance and on the possible mechanism of efficiency roll-off in NC LED.

Encapsulation of Organic Light Emitting Diodes by PDMS Stamping

2015 ◽  
Vol 1132 ◽  
pp. 166-184
Author(s):  
V.C. Anye ◽  
W.O. Akande ◽  
M.G. Zebaze Kana ◽  
W.O. Soboyejo
Keyword(s):  
Light Emitting Diodes ◽  
Single Layer ◽  
Mechanical Tests ◽  
Organic Light Emitting Diodes ◽  
Polydimethyl Siloxane ◽  
Brazilian Disk ◽  
Light Emitting ◽  
Force Microscopy ◽  
Organic Light ◽  
Microscopy Techniques

This paper presents results of the improvement of the lifetime of organic light emitting diodes (OLEDs) by encapsulation with polydimethyl siloxane (PDMS). This polymer is very effective in protecting the device from degradation in oxygen and moisture rich environments. This is captured in the results obtained for full immersion and storage tests of encapsulated single layer devices based on MEH:PPV as the active layer. Mechanical tests were carried out to ascertain the strength (adhesion) of the interface between the encapsulating layer and the device cathode material, aluminum (Al) using both centrally-cracked Brazilian Disk, CCBD and force microscopy techniques. The encapsulated devices provided an average of 90 minutes of illumination while the bare devices provided illumination for about 3 minutes. Such a reproducible stamping technique is more appropriate due to the low processing temperatures, inherent flexibility, device compatibility and mechanical robustness at low costs.

The topography of organic light-emitting diode-component functional layers as studied by atomic force microscopy

2004 ◽  
Vol 14 (4) ◽  
pp. 155-157 ◽  
Author(s):  
Oksana V. Kotova ◽  
Svetlana V. Eliseeva ◽  
Elena V. Perevedentseva ◽  
Tatyana F. Limonova ◽  
Raida A. Baigeldieva ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Organic Light

Hexagonal Pyramids Shaped GaN Light Emitting Diodes Array by N-polar Wet Etching

2013 ◽  
Vol 1538 ◽  
pp. 353-359
Author(s):  
Jun Ma ◽  
Liancheng Wang ◽  
Zhiqiang Liu ◽  
Guodong Yuan ◽  
Xiaoli Ji ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Active Regions ◽  
Wet Etching ◽  
Conductive Atomic Force Microscopy ◽  
Light Emitting ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Vertical Injection ◽  
Reduced Density

ABSTRACTIn this work, we investigated the influence of N-polar wet etching on the properties of nitride-based hexagonal pyramids array (HPA) vertical-injection light emitting diodes (V-LEDs). The cathodeluminescence images showed the randomly distribution of hexagonal pyramids with isolated active regions. The transmission electron microscopy images demonstrated the reduced density of threading dislocations. The IQE was estimated by temperature dependence of photoluminescence, which showed 30% increase for HPA V-LEDs compared with broad area (BA) V-LEDs. The improved extraction efficiency was verified by finite difference time domain simulation, which was 20% higher than that of roughened BA V-LEDs. The electrical properties of HPA V-LEDs were measured by conductive atomic force microscopy (CAFM) measurements. HPA V-LEDs exhibited much lower leakage current due to the improved crystal quality.

scholarly journals Characteristic Evaluation of Organic Light-Emitting Diodes Prepared with Stamp Printing Technique

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Apisit Chittawanij ◽  
Kitsakorn Locharoenrat
Keyword(s):  
Thin Film ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Organic Thin Film ◽  
Light Emitting ◽  
Force Microscopy ◽  
Organic Light ◽  
Printing Technique

We have reported on a stamp printing technique that uses PET release film as a printing stamp to deposit TPBi thin film served as the electron transport layer of the organic light-emitting diodes. TPBi thin film was printed with a good uniformity and resolution. Effect of deposition conditions on optical and electrical properties and surface roughness of TPBi thin film have been studied under spectroscopy and atomic force microscopy, respectively. It is found that characteristic of TPBi thin film is improved via controlled stamp temperature and time. Since TPBi thin film exhibits the surface morphology comparable to that of conventional spin-coating thin film, our findings suggest that PET release film-based stamp printing approach is possible to use as an alternative deposition of the organic thin film as compared with a traditional one.

Sign in / Sign up

Export Citation Format

Share Document