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Síntesis, estructura electrónica, embalaje molecular / evolución de la morfología y movilidad de los transportadores
Lei Zhang1, Nicholas S Colella, Feng Liu
1Department of Polymer Science and Engineering, Conte Research Center, University of Massachusetts, Amherst, Massachusetts 01003, USA.
Journal of the American Chemical Society
|December 13, 2012
Resumen
Los oligotiofenos conjugados monodispersos muestran un mejor transporte de carga con una longitud de cadena decreciente, impulsado por la cristalinidad y la orientación del cristal, no solo por el peso molecular. Esto hace avanzar la comprensión de los semiconductores de oligotiofeno.
Área de la Ciencia:
- La electrónica orgánica es la electrónica orgánica.
- Ciencia de los materiales ciencia de los materiales.
- Física del estado sólido física del estado sólido.
Sus antecedentes:
- Los oligotiofenos conjugados monodispersos son sistemas modelo vitales para los polímeros polidispersos.
- Exhiben propiedades únicas de transporte óptico, optoelectrónico y de carga.
Objetivo del estudio:
- Sintetice y caracterice los oligotiofenos monodispersos hasta seis unidades de didodecylquaterthiophene (DDQT).
- Investigar su estructura electrónica, empaque molecular, morfología y transporte de carga.
- Correlacione estas propiedades con la longitud de conjugación y el peso molecular.
Principales métodos:
- Síntesis de oligotiofenos con diferentes unidades de repetición de DDQT.
- Análisis de la estructura cristalina de rayos X para la conformación molecular y el empaque.
- Incidencia de pastoreo dispersión de rayos X para la morfología de película delgada.
- Medidas de carga de transporte (por ejemplo, movilidad).
Principales resultados:
- Estructura electrónica convergente a poli-3,3"-didodecilo-cuaterthiophene (PQT-12) en la longitud de la conjugación efectiva.
- Los oligotiofenos mostraron sinconformaciones y cadenas de alquilo dobladas para minimizar el obstáculo estérico.
- La morfología evolucionó de una pequeña molécula similar a un empaque similar a un polímero cerca de la longitud de conjugación efectiva.
- La movilidad del portador de carga aumentó con la disminución de la longitud de la cadena.
Conclusiones:
- La movilidad del portador se rige principalmente por la cristalinidad y la desorientación de los granos de cristal, no solo por el peso molecular.
- La optimización de la cristalinidad y la orientación en el plano es clave para mejorar la movilidad de los oligotiofenos de bajo peso molecular.
- Estableció un vínculo fundamental entre la longitud de conjugación, el empaque molecular y el transporte de carga en semiconductores de oligotiofeno.
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