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El ordenamiento de alta lamelaridad y la red pi amorfa en copolímeros de cadena corta tiazolothiazol-tiofeno conducen
Itaru Osaka1, Rui Zhang, Geneviève Sauvé
1Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
Journal of the American Chemical Society
|February 3, 2009
Resumen
Las altas movilidades de portador en polímeros semiconductores se pueden lograr sin espina dorsal larga o cadenas laterales cristalinas. Los nuevos sistemas similares al politiofeno demuestran un excelente rendimiento electrónico a pesar de su estructura desordenada.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Electrónica orgánica y electrónica orgánica.
- La ciencia de los polímeros es la ciencia de los polímeros.
Sus antecedentes:
- Los poli ((alquiltiofenos) son polímeros semiconductores ampliamente estudiados para la electrónica orgánica.
- La movilidad del portador es crucial para el rendimiento electrónico y a menudo se mejora al aumentar la longitud de la columna vertebral o la cristalinidad de la cadena lateral.
- Investigaciones anteriores sugirieron que una alta cristalinidad y largas columnas vertebrales son necesarias para un buen rendimiento electrónico.
Objetivo del estudio:
- Para investigar el rendimiento electrónico de los polímeros semiconductores basados en tiofeno con unidades de tiazolothiazol (PTzQT).
- Para determinar si las espinas dorsales conjugadas largas y las cadenas laterales altamente cristalinas son esenciales para la alta movilidad del portador.
- Explorar la relación entre la estructura material, el desorden y las propiedades de transporte de carga.
Principales métodos:
- Síntesis de polímeros semiconductores basados en tiofeno (PTzQT).
- Medición de las movilidades de las naves transportadoras.
- Análisis térmico y dispersión de rayos X para evaluar la cristalinidad y el empaque molecular.
- Microscopía de fuerza atómica (AFM) para analizar la morfología a nanoescala.
Principales resultados:
- Los polímeros PTzQT exhibieron altas movilidades de portadores (aprox. 0,3 cm2/Vs) a pesar de su bajo peso molecular y su supresión de la cristalinidad de la cadena lateral.
- Los materiales mostraron una naturaleza altamente desordenada a nanoescala, formando superestructuras amorfas similares.
- La movilidad del portador aumentó con la longitud de las cadenas laterales de alquilo, correlacionándose con las características de rugosidad de la superficie.
Conclusiones:
- La alta movilidad del portador en sistemas similares al politiofeno se puede lograr sin espina dorsal conjugada larga o cristalinidad significativa de la cadena lateral.
- El desorden del material y la rugosidad superficial a nanoescala juegan un papel crítico en el control del transporte de carga en estos sistemas.
- Estos hallazgos desafían las estrategias convencionales para mejorar la movilidad en semiconductores orgánicos.
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