Encapsulation of aggregation-caused quenching dye in metal-organic framework as emissive layer of organic light-emitting diodes

2021 ◽  
pp. 111452
Author(s):  
Vetiga Somjit ◽  
Chokchai Kaiyasuan ◽  
Phakawan Thinsoongnoen ◽  
Taweesak Pila ◽  
Vinich Promarak ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Metal Organic Framework ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Emissive Layer ◽  
Organic Light ◽  
Metal Organic ◽  
Organic Framework

Anthracene based metal-organic framework showing efficient angle-dependent polarized emission, luminescent thermometry, and photoelectronic response

2022 ◽  
Author(s):  
Ji-Rui Zhang ◽  
Hao-Yi Zhang ◽  
Jia-hui Guo ◽  
Zi-Han Liu ◽  
Cheng-Yu Ma ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Biological Imaging ◽  
Organic Light Emitting Diodes ◽  
Photoelectric Device ◽  
Light Emitting ◽  
Organic Light ◽  
Polarized Emission ◽  
Metal Organic

The development of luminescent metal-organic frameworks (MOFs) has attracted extensive attention due to their applications in photoelectric device, organic light-emitting diodes (OLEDs), anti-counterfeiting, biological imaging and so on. In this...

Electrically and Optically Detected Electron Paramagnetic Resonance in Blue Organic Light Emitting Diodes

2021 ◽  
Author(s):  
◽  
Rebecca Jane Sutton
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Great Promise ◽  
Paramagnetic Resonance ◽  
Light Emitting ◽  
Emissive Layer ◽  
Organic Light ◽  
Optically Detected ◽  
Electron Paramagnetic

<p>Organic light emitting diodes (OLEDs) are an emerging technology based on electrically conducting polymer films, with great promise for large area lighting and flexible ultra-thin displays. However, despite the rapid technological development, there is still a poor understanding of the degradation and spindependent recombination processes that take place inside an OLED. In this thesis, Electron Paramagnetic Resonance (EPR) was used to investigate these processes in blue-emitting OLEDs.  A successful procedure was developed and refined for fabricating OLEDs with the structure ITO/PEDOT:PSS/emissive layer/Al/Ag, with and without the PEDOT:PSS hole-transporting layer. The organic emissive layer was either F8BT, PFO, or PVK:OXD-7:FIrpic (PB). These OLEDs were fabricated in air and with a geometry optimised for EPR experiments. Critical features for satisfactory devices were found to be a sufficiently thick organic layer and minimal exposure to the air.  A compact apparatus was developed for simultaneous light output, current, and voltage measurements on the OLEDs while in an inert glove box environment. Electroluminescence and current-voltage parameters measured for these devices showed predominantly trap-controlled space-charge-limited conduction.   OLEDs with PFO as the emissive layer and with a PEDOT:PSS layer were investigated with conventional, electrically-detected (ED) and optically-detected (OD) EPR techniques. EDEPR and ODEPR signals were observed at ~9.2 GHz and in the low (<50 mT) and high (~330 mT) magnetic field regimes and were found to change markedly with time during operation as the device degraded. The low field signals initially showed a composite broad quenching and superimposed narrow enhancing response centred around zero field strength. These signals were attributed to magneto-resistance (MR) and magneto-electroluminescence (MEL). Following operational ageing, a third, narrow quenching line was observed in the MR and the ratio of the initial two MR responses changed substantially. These effects are tentatively attributed to a hyperfine interaction.  For both EDEPR and ODEPR, quenching high field resonances with a g-value (gyromagnetic ratio) of 2.003±0.001 were observed. The current-quenching resonance gradually diminished during operation and after 4–5 hours was replaced by a current-enhancing resonance. The appearance of this latter resonance could be explained by chemical changes in the OLED due to the diffusion of oxygen through the device from the oxygen-plasma-treated ITO. A working model is proposed which can explain this observed change as spindependent trapping and recombination at free radicals, although the model requires further experimentation to test its validity.</p>

Color stable phosphorescent white organic light-emitting diodes with double emissive layer structure

2013 ◽  
Vol 14 (4) ◽  
pp. 1183-1188 ◽  
Author(s):  
Young Hoon Son ◽  
Mi Jin Park ◽  
Young Jae Kim ◽  
Joong Hwan Yang ◽  
Jung Soo Park ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Layer Structure ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Emissive Layer ◽  
Organic Light

Color Stability of Blue Phosphorescent Organic Light-Emitting Diodes with Undoped Layer in Emissive Layer

2012 ◽  
Vol 51 (9S2) ◽  
pp. 09MH02
Author(s):  
Chan-Jae Lee ◽  
Chang-Jun Maeng ◽  
Jin-Ho Ahn ◽  
Jeong-No Lee ◽  
Min-Gi Kwak
Keyword(s):  
Light Emitting Diodes ◽  
Color Stability ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Emissive Layer ◽  
Organic Light ◽  
Blue Phosphorescent
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