Prediction of Charge Mobility in Amorphous Organic Materials through the Application of Hopping Theory

2011 ◽  
Vol 7 (8) ◽  
pp. 2556-2567 ◽  
Author(s):  
Choongkeun Lee ◽  
Robert Waterland ◽  
Karl Sohlberg
Keyword(s):  
Organic Materials ◽  
Charge Mobility

ChemInform Abstract: Computational Methods for Design of Organic Materials with High Charge Mobility

ChemInform ◽  
2010 ◽  
Vol 41 (17) ◽  
Author(s):  
Linjun Wang ◽  
Guangjun Nan ◽  
Xiaodi Yang ◽  
Qian Peng ◽  
Qikai Li ◽  
...  
Keyword(s):  
Computational Methods ◽  
Organic Materials ◽  
Charge Mobility ◽  
High Charge

Application of hopping theory for the prediction of charge mobility in amorphous organic materials

2012 ◽  
Vol 1402 ◽  
Author(s):  
Karl Sohlberg ◽  
Choongkeun Lee ◽  
Robert Waterland
Keyword(s):  
Detailed Analysis ◽  
Organic Materials ◽  
Reorganization Energy ◽  
Hole Mobility ◽  
Charge Hole ◽  
Numerical Approximations ◽  
Material Density ◽  
Charge Mobility ◽  
Lower Charge ◽  
Insight Into

ABSTRACTThe application of hopping theory for the prediction of charge (hole) mobility in amorphous organic molecular materials is studied in detail. Application is made to amorphous cells of N,N’-diphenyl-N,N’-bis-(3-methylphenylene)-1,1’-diphenyl-4,4’-diamine (TPD), N4,N4’-di(biphenyl-3-yl)-N4,N4’-diphenylbiphenyl-4,4’-diamine (mBPD), 1,1-bis-(4,4’-diethylaminophenyl)-4,4-diphenyl-1,3,butadinene (DEPB), N1,N4-di(naphthalen-1-yl)-N1,N4-diphenylbenzene-1,4-diamine (NNP), and N,N’-bis[9,9-dimethyl-2-fluorenyl]-N,N’-diphenyl-9,9-dimethylfluorene-2,7-diamine (pFFA). Detailed analysis of the computation of each of the parameters in the equations for hopping rate is presented, including studies of their convergence with respect to various numerical approximations. Based on these convergence studies, the most robust practical methodology is applied to investigate the dependence of mobility on such parameters as the monomer reorganization energy, the monomer-monomer coupling and the material density. The results give insight into what factors should be controlled to develop materials with higher (or lower) charge (hole) mobility, and what will be required to improve the accuracy of predictions of mobility in amorphous organic materials.

Computational methods for design of organic materials with high charge mobility

2010 ◽  
Vol 39 (2) ◽  
pp. 423-434 ◽  
Author(s):  
Linjun Wang ◽  
Guangjun Nan ◽  
Xiaodi Yang ◽  
Qian Peng ◽  
Qikai Li ◽  
...  
Keyword(s):  
Computational Methods ◽  
Organic Materials ◽  
Charge Mobility ◽  
High Charge

Electrically conductive Covalent Organic Frameworks: Bridging the Fields of Organic Metals and 2D Materials

2021 ◽  
Author(s):  
Manuel Souto ◽  
Dmitrii Perepichka
Keyword(s):  
Organic Materials ◽  
2D Materials ◽  
Covalent Organic Frameworks ◽  
Electrically Conductive ◽  
Charge Mobility ◽  
High Charge ◽  
Organic Metals ◽  
Electrical Devices

The discovery of organic metals in 1970s opened the door to the design of electrical devices based on traditionally inert (insulating) organic materials. More recently, demonstration of record-high charge mobility...

Application of Improved Voltage Compensation in the SEM to Imaging of Organic Materials

1973 ◽  
Vol 31 ◽  
pp. 444-445
Author(s):  
P.J. Killingworth ◽  
M. Warren
Keyword(s):  
Electron Beam ◽  
Organic Materials ◽  
Operating Parameters ◽  
Low Density ◽  
Beam Diameter ◽  
Incident Electron Beam ◽  
Specimen Material ◽  
Voltage Compensation ◽  
Selection Of ◽  
Scanning Electron

Ultimate resolution in the scanning electron microscope is determined not only by the diameter of the incident electron beam, but by interaction of that beam with the specimen material. Generally, while minimum beam diameter diminishes with increasing voltage, due to the reduced effect of aberration component and magnetic interference, the excited volume within the sample increases with electron energy. Thus, for any given material and imaging signal, there is an optimum volt age to achieve best resolution.In the case of organic materials, which are in general of low density and electric ally non-conducting; and may in addition be susceptible to radiation and heat damage, the selection of correct operating parameters is extremely critical and is achiev ed by interative adjustment.

200kv superconducting cryo electron microscope

1987 ◽  
Vol 45 ◽  
pp. 642-643
Author(s):  
M. Iwatsuki ◽  
Y. Kokubo ◽  
Y. Harada ◽  
J. Lehman
Keyword(s):  
Electron Microscope ◽  
Structure Analysis ◽  
Organic Materials ◽  
Strong Interactions ◽  
Specimen Preparation ◽  
Great Effort ◽  
Electron Microscopic ◽  
Crystal Fields ◽  
Special Skill ◽  
Long Time

In recent years, the electron microscope has been significantly improved in resolution and we can obtain routinely atomic-level high resolution images without any special skill. With this improvement, the structure analysis of organic materials has become one of the interesting targets in the biological and polymer crystal fields.Up to now, X-ray structure analysis has been mainly used for such materials. With this method, however, great effort and a long time are required for specimen preparation because of the need for larger crystals. This method can analyze average crystal structure but is insufficient for interpreting it on the atomic or molecular level. The electron microscopic method for organic materials has not only the advantage of specimen preparation but also the capability of providing various information from extremely small specimen regions, using strong interactions between electrons and the substance. On the other hand, however, this strong interaction has a big disadvantage in high radiation damage.

STM of freeze-fracture replicas: Problems and promises

1993 ◽  
Vol 51 ◽  
pp. 68-69
Author(s):  
J. T. Woodward ◽  
J. A. N. Zasadzinski
Keyword(s):  
Scanning Tunneling Microscope ◽  
Organic Materials ◽  
Freeze Fracture ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
Molecular Scale ◽  
Organic Surfaces ◽  
Metal Layers ◽  
Conductive Surfaces

The Scanning Tunneling Microscope (STM) offers exciting new ways of imaging surfaces of biological or organic materials with resolution to the sub-molecular scale. Rigid, conductive surfaces can readily be imaged with the STM with atomic resolution. Unfortunately, organic surfaces are neither sufficiently conductive or rigid enough to be examined directly with the STM. At present, nonconductive surfaces can be examined in two ways: 1) Using the AFM, which measures the deflection of a weak spring as it is dragged across the surface, or 2) coating or replicating non-conductive surfaces with metal layers so as to make them conductive, then imaging with the STM. However, we have found that the conventional freeze-fracture technique, while extremely useful for imaging bulk organic materials with STM, must be modified considerably for optimal use in the STM.

Stabilizing pyritic material

1989 ◽  
Vol 4 ◽  
pp. 244-248 ◽  
Author(s):  
Donald L. Wolberg
Keyword(s):  
Significant Contribution ◽  
Organic Materials ◽  
Sedimentary Rocks ◽  
Iron Sulfides ◽  
Decomposition Products ◽  
Iron Minerals ◽  
Pyrite Formation ◽  
Organic Sediments ◽  
Freshwater Environments

The minerals pyrite and marcasite (broadly termed pyritic minerals) are iron sulfides that are common if not ubiquitous in sedimentary rocks, especially in association with organic materials (Berner, 1970). In most marine sedimentary associations, pyrite and marcasite are associated with organic sediments rich in dissolved sulfate and iron minerals. Because of the rapid consumption of sulfate in freshwater environments, however, pyrite formation is more restricted in nonmarine sediments (Berner, 1983). The origin of the sulfur in nonmarine environments must lie within pre-existing rocks or volcanic detritus; a relatively small, but significant contribution may derive from plant and animal decomposition products.

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