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Polímeros conjugados π muy pequeños con tienoquinoides extendidos
Kohsuke Kawabata1, Masahiko Saito1, Itaru Osaka1
1Emergent Molecular Function Research Group, Center for Emergent Matter Science, RIKEN , Wako, Saitama 351-0198, Japan.
Journal of the American Chemical Society
|May 26, 2016
Resumen
Se sintetizaron nuevos polímeros conjugados π con carácter quinoidal, con tienoquinoides como unidades deficientes en electrones. PBDTD4T logró una brecha de banda muy pequeña (0,88 eV) y un transporte de carga ambipolar, prometedor para la electrónica orgánica.
Área de la Ciencia:
- Ciencias de los materiales
- Productos electrónicos orgánicos
- Química de los polímeros
Sus antecedentes:
- La reducción de la brecha de banda de los polímeros π-conjugados es crucial para mejorar su rendimiento en dispositivos electrónicos orgánicos.
- La incorporación del carácter quinoidal es una estrategia efectiva para la reducción de la brecha de banda.
Objetivo del estudio:
- Para sintetizar nuevos polímeros conjugados π con fuertes unidades tienoquinoides con deficiencia de electrones.
- Investigar el efecto de las unidades de tienoquinoide (2,2'-biotiofeno-5,5'-diona, BTD) y benzoditiofendiona (benzo[1,2-b:4,5-b']diotiofeno-2,6-diona, BDTD) en las propiedades de los polímeros.
- Evaluar las características de transporte de carga y las propiedades ópticas de los polímeros sintetizados.
Principales métodos:
- Síntesis de nuevos polímeros π-conjugados, PBTD4T y PBDTD4T, que incorporan unidades de aceptación de BTD y BDTD.
- Caracterización de las propiedades del polímero, incluidos los niveles de energía LUMO, los espacios de banda y la transparencia.
- Evaluación de las propiedades de transporte de carga, específicamente de los agujeros y la movilidad de los electrones.
Principales resultados:
- PBTD4T exhibió un LUMO de -3.77 eV y una brecha de banda de 1.28 eV.
- PBDTD4T demostró un LUMO más profundo de -4.04 eV y una brecha de banda significativamente más pequeña de 0.88 eV, con una alta transparencia visible.
- Tanto PBTD4T como PBDTD4T mostraron un transporte de carga ambipolar equilibrado, superando el rendimiento de un polímero de referencia (PTTD4T).
Conclusiones:
- La incorporación de unidades BDTD conduce a una reducción sustancial de la brecha de banda y a una mayor actividad en el infrarrojo cercano.
- Los polímeros sintetizados exhiben propiedades prometedoras de transporte de carga ambipolar equilibrada.
- Estos polímeros conjugados con π son adecuados para fabricar dispositivos electrónicos orgánicos de próxima generación.
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