Improved Operational Stability of Polymer Light-Emitting Diodes Based on Silver Nanowire Electrode Through Pre-Bias Conditioning Treatment

2014 ◽  
Vol 24 (41) ◽  
pp. 6465-6472 ◽  
Author(s):  
Yonghee Lee ◽  
Minwon Suh ◽  
Donghyuk Kim ◽  
Dongchan Lee ◽  
Hyein Chang ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Silver Nanowire ◽  
Operational Stability ◽  
Light Emitting ◽  
Conditioning Treatment ◽  
Polymer Light Emitting Diodes

scholarly journals Self-powered, ultraflexible photonic skin for continuous bio-signal detection via air-operation-stable polymer light-emitting diodes

2020 ◽  
Author(s):  
Hiroaki Jinno ◽  
Tomoyuki Yokota ◽  
Mari Koizumi ◽  
Wakako Yukita ◽  
Masahiko Saito ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Light Emitting Diodes ◽  
Ambient Air ◽  
Optical Devices ◽  
Operational Stability ◽  
Power Sources ◽  
Light Emitting ◽  
Polymer Light Emitting Diodes ◽  
Self Powered

Abstract Flexible organic optical devices have been used extensively in next-generation wearable electronics owing to advantages such as light-weight, thinness, and flexibility. Making such organic optical devices ultrathin enables long-term monitoring of health conditions owing to the increased conformability of ultrathin devices to human skin. Long-term biological signal monitoring also requires the integration of organic optical devices with an energy harvesting power sources which does not require recharging; to make devices self-powered. However, system-level integration of such thin organic optical sensors with power sources is challenging. An important obstacle to this type of integration is the insufficient operational stability of ultrathin organic light-emitting diodes under ambient air conditions. Here we develop an ultrathin self-powered organic optical system for photoplethysmogram (PPG) monitoring. This system consists of three types of ultrathin electronic devices: polymer light-emitting diodes (PLEDs), organic solar cells, and organic photodetectors. By adopting an inverted structure and a polyethylenimine ethoxylated layer doped with 8-hydroxyquinolinato-lithium as the electron-transport layer, PLEDs exhibit improved operational stability under ambient air conditions without external encapsulation. Ultraflexible PLEDs with no passivation retain 70% of the initial luminance lifetime of 11.3 h under ambient air. Integrated optical sensors exhibit a high linearity with the light intensity exponent of 0.98 by PLED light source. Such self-powered, ultraflexible PPG sensors can perform long-term stable monitoring of blood pulse signals on human hands.

Efficient Flexible Phosphorescent Polymer Light-Emitting Diodes Based on Silver Nanowire-Polymer Composite Electrode

2011 ◽  
Vol 23 (46) ◽  
pp. 5563-5567 ◽  
Author(s):  
Lu Li ◽  
Zhibin Yu ◽  
Weili Hu ◽  
Chia-hao Chang ◽  
Qi Chen ◽  
...  
Keyword(s):  
Polymer Composite ◽  
Composite Electrode ◽  
Light Emitting Diodes ◽  
Silver Nanowire ◽  
Light Emitting ◽  
Polymer Light Emitting Diodes

Highly Flexible Silver Nanowire Electrodes for Shape-Memory Polymer Light-Emitting Diodes

2010 ◽  
Vol 23 (5) ◽  
pp. 664-668 ◽  
Author(s):  
Zhibin Yu ◽  
Qingwu Zhang ◽  
Lu Li ◽  
Qi Chen ◽  
Xiaofan Niu ◽  
...  
Keyword(s):  
Shape Memory ◽  
Light Emitting Diodes ◽  
Shape Memory Polymer ◽  
Silver Nanowire ◽  
Light Emitting ◽  
Polymer Light Emitting Diodes

Efficient white polymer light-emitting diodes employing a silver nanowire–polymer composite electrode

2012 ◽  
Vol 14 (41) ◽  
pp. 14249 ◽  
Author(s):  
Lu Li ◽  
Zhibin Yu ◽  
Chia-hao Chang ◽  
Weili Hu ◽  
Xiaofan Niu ◽  
...  
Keyword(s):  
Polymer Composite ◽  
Composite Electrode ◽  
Light Emitting Diodes ◽  
Silver Nanowire ◽  
Light Emitting ◽  
Polymer Light Emitting Diodes

Injecting Inter-Layers and the Built-in Potential of Blue Polymer Light-Emitting Diodes

2000 ◽  
Vol 660 ◽  
Author(s):  
Thomas M. Brown ◽  
Ian S. Millard ◽  
David J. Lacey ◽  
Jeremy H. Burroughes ◽  
Richard H. Friend ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Light Emitting Diodes ◽  
Basic Structure ◽  
Thin Layers ◽  
Carrier Injection ◽  
Semiconducting Polymer ◽  
Light Emitting ◽  
Physical Mechanisms ◽  
Organic Solid ◽  
Polymer Light Emitting Diodes

ABSTRACTThe semiconducting-polymer/injecting-electrode heterojunction plays a crucial part in the operation of organic solid state devices. In polymer light-emitting diodes (LEDs), a common fundamental structure employed is Indium-Tin-Oxide/Polymer/Al. However, in order to fabricate efficient devices, alterations to this basic structure have to be carried out. The insertion of thin layers, between the electrodes and the emitting polymer, has been shown to greatly enhance LED performance, although the physical mechanisms underlying this effect remain unclear. Here, we use electro-absorption measurements of the built-in potential to monitor shifts in the barrier height at the electrode/polymer interface. We demonstrate that the main advantage brought about by inter-layers, such as poly(ethylenedioxythiophene)/poly(styrene sulphonic acid) (PEDOT:PSS) at the anode and Ca, LiF and CsF at the cathode, is a marked reduction of the barrier to carrier injection. The electro- absorption results also correlate with the electroluminescent characteristics of the LEDs.

Geometrically isomeric [Ir(iqbt)(ppy)(hpa)] complexes with differential molecule orientations for efficient near-infrared (NIR) polymer light-emitting diodes (PLEDs)

2021 ◽  
Vol 9 (36) ◽  
pp. 12068-12072
Author(s):  
Wentao Li ◽  
Jiaxiang Liu ◽  
Baowen Wang ◽  
Siyu Hou ◽  
Xingqiang Lü ◽  
...  
Keyword(s):  
Near Infrared ◽  
Light Emitting Diodes ◽  
Dipole Transition ◽  
Transition Dipole ◽  
Light Emitting ◽  
Horizontal Orientation ◽  
Polymer Light Emitting Diodes

Based on geometrical isomerisation of [Ir(C^N1)(C^N2)((N^O))]-tris-heteroleptic Ir(iii)-complexes, the augmented transition dipole transition (TMD) with a preferential horizontal orientation, which is beneficial for their NIR-phosphorescence, is reported.

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