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Efectos impares en el transporte de carga a través de SAMs basados en n-alcanetiolato
Mostafa Baghbanzadeh1, Felice C Simeone, Carleen M Bowers
1Department of Chemistry and Chemical Biology, Harvard University , 12 Oxford Street, Cambridge, Massachusetts 02138, United States.
Journal of the American Chemical Society
|November 8, 2014
Resumen
El transporte de carga a través de monocapas autoensambladas (SAM) muestra un efecto impar-par en los electrodos de oro, pero no en los de plata. Esta diferencia en la densidad de corriente se atribuye al número de átomos de carbono en las cadenas de alquilo.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Química de las superficies.
- La electrónica molecular es la electrónica molecular.
Sus antecedentes:
- Las monocapas autoensambladas (SAM) son cruciales en la electrónica molecular para controlar el transporte de cargas.
- Comprender la influencia de la estructura molecular en las propiedades electrónicas es clave para la optimización de dispositivos.
Objetivo del estudio:
- Para investigar el efecto de la paridad de la longitud de la cadena de alquilo (átomos de carbono impares versus pares) en el transporte de carga a través de SAMs.
- Para comparar este efecto en diferentes electrodos metálicos (oro y plata).
Principales métodos:
- Fabricación de uniones moleculares con la estructura M(TS) /SAM//Ga2O3/EGaIn (M = Au o Ag).
- Medición de las características de densidad-tensión de corriente (J(V)) a través de SAMs.
- Análisis estadístico de la densidad de corriente del túnel (J0) y la constante de decaimiento del túnel (β).
Principales resultados:
- Se observó un efecto par e impar estadísticamente significativo en el transporte de carga para los SAM en los electrodos de oro, pero no en la plata.
- Mientras que la densidad de corriente de inyección (J0) difería entre las longitudes de cadena impares y pares en el oro, la constante de decaimiento de túnel (β) seguía siendo indistinguible.
- Las características eléctricas eran similares entre los electrodos de oro y plata, lo que indica una influencia mínima del ángulo de inclinación de la cadena de alquilo en la densidad de corriente de inyección.
Conclusiones:
- El número de átomos de carbono en los SAMs n-alcanetiolato influye en el transporte de carga de manera diferente en las superficies de oro y plata.
- El efecto impar y par observado en el oro sugiere interacciones específicas o arreglos de empaque relacionados con la paridad de la cadena.
- La constante de desintegración del túnel es un parámetro robusto, no afectado por la paridad de la cadena o el material del electrodo en este estudio.
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