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Espectroscopia Raman in situ de cambios estructurales inducidos por sesgo en las uniones electrónicas moleculares de
Aletha M Nowak1, Richard L McCreery
1Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA.
Journal of the American Chemical Society
|December 17, 2004
Resumen
Las uniones electrónicas moleculares que utilizan nitroazobenzeno (NAB) mostraron un ciclo redox reversible con voltaje positivo. El voltaje negativo causó cambios irreversibles, lo que indica un complejo mecanismo de conducción que involucra a NAB y óxido de titanio.
Área de la Ciencia:
- La electrónica molecular es la electrónica molecular.
- Ciencia de los materiales ciencia de los materiales.
- Espectro electroquímica electroquímica.
Sus antecedentes:
- Las uniones electrónicas moleculares son clave para los dispositivos a nanoescala.
- El nitroazobenzeno (NAB) es una molécula con aplicaciones electrónicas potenciales.
- Comprender el comportamiento molecular bajo sesgo eléctrico es crucial.
Objetivo del estudio:
- Investigar los cambios estructurales in situ de NAB en las uniones moleculares bajo voltaje aplicado.
- Para correlacionar los datos espectroscópicos con las mediciones eléctricas para dilucidar los mecanismos de conducción.
Principales métodos:
- Construcción de uniones electrónicas moleculares de carbono/nitroazobenceno/titanio/oro.
- Espectroscopia Raman in situ para el monitoreo de la estructura molecular.
- Aplicación de sesgos eléctricos desde +3 V hasta -3 V.
- Correlación con las mediciones de corriente / tensión (I / V).
Principales resultados:
- El voltaje positivo (+3 V) indujo la reoxidación reversible de NAB.
- El voltaje negativo (-2 a -3 V) causó una pérdida irreversible del grupo nitro y una disminución de la intensidad Raman.
- Los cambios espectrales se correlacionan con las curvas I/V, sugiriendo rectificación y conmutación.
Conclusiones:
- El mecanismo de conducción incluye tanto NAB como óxido de titanio.
- La inyección del portador en el óxido de titanio semiconductor o la reducción a una forma conductiva son los mecanismos propuestos.
- El estudio proporciona información sobre la conmutación y rectificación molecular en las uniones electrónicas.
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