scholarly journals Dynamical Mechanism of Polarons and Bipolarons in Poly(p-Phenylene Vinylene)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Fábio Luís de Oliveira Paula ◽  
Leonardo Luiz e Castro ◽  
Luiz Antonio Ribeiro Junior ◽  
Rafael Timóteo de Sousa Júnior ◽  
Geraldo Magela e Silva ◽  
...  
Keyword(s):  
Transport Mechanism ◽  
Tight Binding ◽  
Lattice Relaxation ◽  
Phenylene Vinylene ◽  
Dynamical Mechanism ◽  
Light Emitting ◽  
Chemical Structures ◽  
Relaxation Effects ◽  
Local Lattice ◽  
The Relationship

AbstractStudies on Poly(p-Phenylene Vinylene) (PPV) and derivatives have experienced enormous growth since they were successfully used to fabricate the first efficient prototypes of Polymer Light-Emitting Diodes in the 90s. Despite this rapid progress, understanding the relationship between charge transport and the morphology in these materials remains a challenge. Here, we shed light on the understanding of the transport mechanism of polarons and bipolarons in PPVs by developing a two-dimensional tight-binding approach that includes lattice relaxation effects. Remarkably, the results show that the PPV lattice loses the energy related to its conjugation during time by transferring this amount of energy to electrons. Such a process for energy transfer permits the quasiparticles to overcome the potential barrier imposed by the local lattice deformations, that are formed in the presence of an additional charge and, consequently, their electric field assisted transport takes place. Within the framework of this transport mechanism, a better insight into the origin of the carrier mobility in PPV and derivatives can be achieved and would be a useful guide for improving their chemical structures and morphologies.

scholarly journals Unravelling the electron injection/transport mechanism in organic light-emitting diodes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tsubasa Sasaki ◽  
Munehiro Hasegawa ◽  
Kaito Inagaki ◽  
Hirokazu Ito ◽  
Kazuma Suzuki ◽  
...  
Keyword(s):  
Work Function ◽  
Transport Mechanism ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Electron Injection ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Materials Used

AbstractAlthough significant progress has been made in the development of light-emitting materials for organic light-emitting diodes along with the elucidation of emission mechanisms, the electron injection/transport mechanism remains unclear, and the materials used for electron injection/transport have been basically unchanged for more than 20 years. Here, we unravelled the electron injection/transport mechanism by tuning the work function near the cathode to about 2.0 eV using a superbase. This extremely low-work function cathode allows direct electron injection into various materials, and it was found that organic materials can transport electrons independently of their molecular structure. On the basis of these findings, we have realised a simply structured blue organic light-emitting diode with an operational lifetime of more than 1,000,000 hours. Unravelling the electron injection/transport mechanism, as reported in this paper, not only greatly increases the choice of materials to be used for devices, but also allows simple device structures.

Structure-properties relationship for energy storage redox polymers: a review

2020 ◽  
Vol 40 (5) ◽  
pp. 373-393 ◽  
Author(s):  
Narendra Singh Chundawat ◽  
Nishigandh Pande ◽  
Ghasem Sargazi ◽  
Mazaher Gholipourmalekabadi ◽  
Narendra Pal Singh Chauhan
Keyword(s):  
Energy Storage ◽  
Cost Efficiency ◽  
Energy Storage Materials ◽  
High Scale ◽  
Chemical Structures ◽  
Redox Active ◽  
Potential Applications ◽  
Intelligent Clothing ◽  
The Relationship ◽  
Structure Properties

AbstractRedox-active polymers among the energy storage materials (ESMs) are very attractive due to their exceptional advantages such as high stability and processability as well as their simple manufacturing. Their applications are found to useful in electric vehicle, ultraright computers, intelligent electric gadgets, mobile sensor systems, and portable intelligent clothing. They are found to be more efficient and advantageous in terms of superior processing capacity, quick loading unloading, stronger security, lengthy life cycle, versatility, adjustment to various scales, excellent fabrication process capabilities, light weight, flexible, most significantly cost efficiency, and non-toxicity in order to satisfy the requirement for the usage of these potential applications. The redox-active polymers are produced through organic synthesis, which allows the design and free modification of chemical constructions, which allow for the structure of organic compounds. The redox-active polymers can be finely tuned for the desired ESMs applications with their chemical structures and electrochemical properties. The redox-active polymers synthesis also offers the benefits of high-scale, relatively low reaction, and a low demand for energy. In this review we discussed the relationship between structural properties of different polymers for solar energy and their energy storage applications.

Light-emitting devices based on a poly(p-phenylene vinylene) derivative with ion-coordinating side groups

1999 ◽  
Vol 86 (11) ◽  
pp. 6392-6395 ◽  
Author(s):  
J. Morgado ◽  
R. H. Friend ◽  
F. Cacialli ◽  
B. S. Chuah ◽  
S. C. Moratti ◽  
...  
Keyword(s):  
Phenylene Vinylene ◽  
Light Emitting ◽  
Light Emitting Devices

Highly efficient blue phosphorescent iridium(iii) complexes with various ancillary ligands for partially solution-processed organic light-emitting diodes

2017 ◽  
Vol 5 (36) ◽  
pp. 9306-9314 ◽  
Author(s):  
Peng Tao ◽  
Yuanbing Zhang ◽  
Jiong Wang ◽  
Liuwei Wei ◽  
Hongxin Li ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Solution Processed ◽  
Ancillary Ligands ◽  
Light Emitting ◽  
Chemical Structures ◽  
Highly Efficient ◽  
Organic Light ◽  
Blue Phosphorescent

Excellent blue/pure blue iridium(iii) phosphors with high ΦPL, narrow FWHMs and robust chemical structures are designed for partially solution-processed OLEDs.

Polymer light-emitting diodes based on novel soluble poly(p-phenylene vinylene)

1999 ◽  
Author(s):  
HongJin Jiang ◽  
Yan Zhou ◽  
Jingsong Huang ◽  
Boon Siew Ooi ◽  
Yee Loy Lam ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Phenylene Vinylene ◽  
Light Emitting ◽  
Polymer Light Emitting Diodes ◽  
Soluble Poly

scholarly journals A Device to Measure a Smoker’s Puffing Topography and Real-Time Puff-By-Puff “Tar” Delivery

2014 ◽  
Vol 26 (2) ◽  
Author(s):  
Sandra J. Slayford ◽  
Barrie E. Frost
Keyword(s):  
Real Time ◽  
Light Emitting Diode ◽  
Absolute Error ◽  
Average Error ◽  
Light Emitting ◽  
Light Obscuration ◽  
Test Study ◽  
Added Benefit ◽  
Volume Characteristics ◽  
The Relationship

AbstractA device for measuring the flow, duration and volume characteristics of human puffing behaviour when smoking cigarettes is described. Cigarettes are smoked through a holder comprising a measured pressure drop across a critical orifice. The holder also contains a Light Emitting Diode (LED) and photodetector that measures light obscuration in order to estimate nicotine-free dry particulate matter (NFDPM, “tar”) delivery. All data are recorded on a puff-by-puff basis and displayed in real time. These NFDPM estimates are known as optical “tar” (OT), and are derived from the calibration of the OT measurement versus gravimetric NFDPM yields of cigarettes under a range of smoking regimes. In a test study, puff volumes from 20-80 mL were recorded to ± 6.0% of a pre-set volume, with an absolute error of 4.7 mL for an 80 mL volume drawn on a lit cigarette, and an average error of less than 2.0 mL across the range 20-80 mL. The relationship between NFDPM and OT was linear (R2 = 0.99) and accurate to ± 1.3 mg per cigarette over the range 1-23 mg per cigarette. The device provides an alternative to the widely used part filter methodology for estimating mouth level exposure with an added benefit that no further laboratory smoking replication or analysis is required. When used in conjunction with the part filter methodology, the puffing behaviour recorded can explain anomalies in the data while providing a second independent estimate.

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