Video Experimental Relacionado
Updated: Apr 12, 2026
06:34
Application of a Coupling Agent to Improve the Dielectric Properties of Polymer-Based Nanocomposites
Published on: September 19, 2020
6.4K
Estrategias de donante-puente-receptor molecular para materiales dieléctricos orgánicos de alta capacidad
Henry M Heitzer1, Tobin J Marks1, Mark A Ratner1
1Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.
Journal of the American Chemical Society
|May 16, 2015
Resumen
Los sistemas de donante-puente-aceptor (DBA) exhiben respuestas dieléctricas sintonizables cruciales para la electrónica orgánica. Las monocapas cuadradas logran altas constantes dieléctricas, allanando el camino para el rendimiento avanzado de los transistores.
Área de la Ciencia:
- La electrónica molecular y la fotónica.
- Ciencia de los materiales ciencia de los materiales.
- Química computacional es la química computacional.
Sus antecedentes:
- Los sistemas de donante-puente-aceptor (DBA, por sus siglas en inglés) son conocidos por su sintonizabilidad (hiper) polarizabilidad.
- Los modelos clásicos como el de Clausius-Mossotti son insuficientes para muchos materiales orgánicos.
- Los materiales orgánicos altamente dieléctricos son esenciales para los semiconductores no convencionales.
Objetivo del estudio:
- Investigar la respuesta dieléctrica de las películas delgadas basadas en moléculas DBA.
- Explorar los efectos cooperativos que influyen en las propiedades dieléctricas.
- Proporcionar orientación para el diseño de dieléctricos orgánicos de alta capacidad.
Principales métodos:
- Teoría funcional de la densidad de onda plana (DFT) formalismo.
- Ajuste sistemático de las estructuras de donante, aceptor y puente.
- Análisis de la dependencia de la respuesta dieléctrica de la intensidad del campo eléctrico.
Principales resultados:
- Las películas delgadas de DBA exhiben una gran respuesta dieléctrica debido a los efectos cooperativos donante-aceptante.
- La respuesta dieléctrica es ajustable mediante modificaciones estructurales.
- Las constantes dieléctricas computadas son en gran medida independientes de la función DFT específica.
- Las monocapas de squaraine logran constantes dieléctricas >15.0 y capacidades >6.0 μF/cm2).
Conclusiones:
- Los sistemas DBA ofrecen un camino hacia los dieléctricos orgánicos de alto rendimiento.
- El diseño estructural de las moléculas de DBA puede optimizar las propiedades dieléctricas.
- Las constantes dieléctricas alcanzadas superan significativamente a los dieléctricos orgánicos tradicionales, mejorando las aplicaciones de transistores.
Videos de Conceptos Relacionados
01:18Capacitor With A Dielectric
5.5K
Parallel plate capacitors consist of two conducting plates separated by a certain distance. However, it is mechanically difficult to hold the large plates parallel to each other without actual contact. Hence, a dielectric layer is commonly placed between the plates, which provides an easy solution for holding the plates together with a small gap and increases the capacitance of the capacitor.
Dielectrics are non-conducting materials with no free or loosely bound electrons. When a dielectric is...
Dielectrics are non-conducting materials with no free or loosely bound electrons. When a dielectric is...
5.5K
01:31Dielectric Polarization in a Capacitor
6.7K
The presence of a dielectric medium in a capacitor not only changes the voltage and capacitance but also affects the electric field. In general, dielectrics can be of two types: polar and nonpolar. In a polar dielectric, the positive and negative charges in the molecules are separated by a distance and hence have a permanent dipole moment. In contrast, no such charge separation exists in a nonpolar dielectric, however the nonpolar molecules get polarized in the presence of an external electric...
6.7K
01:25MOS Capacitor
1.9K
A Metal-Oxide-Semiconductor (MOS) capacitor is a fundamental structure used extensively in semiconductor device technology, particularly in the fabrication of integrated circuits and MOSFETs (metal-oxide-semiconductor field-effect transistors). The MOS capacitor consists of three layers: a metal gate, a dielectric oxide, and a semiconductor substrate.
The metal gate is typically made from highly conductive materials such as aluminum or polysilicon. Beneath the metal gate lies a thin layer of...
The metal gate is typically made from highly conductive materials such as aluminum or polysilicon. Beneath the metal gate lies a thin layer of...
1.9K
01:26Susceptibility, Permittivity and Dielectric Constant
3.6K
When placed in an external electric field, a dielectric material gets polarized. The charge density in the dielectric material is given by the sum of the bound and free charge densities, while the total charge density can also be written in terms of the total electric field. The bound charge density can be measured in terms of polarization, leading to the relationship between electric displacement and polarization.
3.6K
00:57Cationic Chain-Growth Polymerization: Mechanism
3.1K
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the...
3.1K
02:51Metal-Ligand Bonds
25.7K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
25.7K