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Extinción de los excitones inducida por polarón de ultralargo alcance en polímeros conjugados aislados
Joshua C Bolinger1, Matthew C Traub, Takuji Adachi
1Center for Nano and Molecular Science and Technology, University of Texas, Austin, TX 78712, USA. jcb2873@mail.utexas.edu
Science (New York, N.Y.)
|February 5, 2011
Resumen
Los polarones de agujero apagan los excitones en polímeros conjugados a largas distancias. Esto ocurre a través de un embudo de energía de varios pasos, no de difusión de excitones libres, revelando nuevos conocimientos sobre la optoelectrónica de polímeros.
Área de la Ciencia:
- La electrónica orgánica es la electrónica orgánica.
- La ciencia de los polímeros es la ciencia de los polímeros.
- La fotofísica es la fotofísica.
Sus antecedentes:
- La recombinación del excitón en polímeros conjugados implica vías radiativas y no radiativas.
- La comprensión de las interacciones excitón-agujero polarón es crucial para los dispositivos optoelectrónicos de polímeros eficientes.
Objetivo del estudio:
- Para visualizar y cuantificar el apagado de la excitación inducido por polarones de agujero en cadenas de polímeros individuales.
- Para determinar la escala de distancia de extinción del excitón por los polarones.
Principales métodos:
- Utilizó una nueva técnica de subdifracción y molécula única: espectroscopia centróide de intensidad modulada por sesgo.
- Investigó el calentamiento de los excitones en nanodomainos de un solo polímero altamente ordenados dentro de una geometría de dispositivo.
Principales resultados:
- Se midió un desplazamiento medio del centroide de 14 nanómetros, lo que indica un apagado a distancias sin precedentes.
- Distancias de transferencia de energía observadas significativamente superiores a las predichas por los modelos de difusión de excitones libres.
- Se demostró que las distancias de apagado son un orden de magnitud mayor que las reportadas anteriormente para polímeros conjugados a granel.
Conclusiones:
- La canalización de energía en múltiples etapas a polarones atrapados y localizados es el mecanismo probable para el apagado de la excitación inducida por polarones.
- Los hallazgos desafían el modelo estándar de enfriamiento del excitón en polímeros conjugados.
- Proporciona información crítica para el diseño de materiales electrónicos orgánicos de próxima generación con un mejor rendimiento.
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