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Efecto de la quiralidad en la formación de excitones triplet ultrarrápidos en los cocristales donantes-receptores de
Georgia C Mantel1, Kyle T Kairys1, Malik L Williams1
1Department of Chemistry, Institute for Quantum Information Research and Engineering, and Center for Molecular and Quantum Transduction, Northwestern University, Evanston, Illinois 60208-3113, United States.
Journal of the American Chemical Society
|July 30, 2025
Resumen
La quiralidad aumenta significativamente la formación de excitones triplet en las células solares orgánicas. Este estudio muestra que los aceptores quirales aumentan el rendimiento de tripletes a través de la selectividad de espín inducida por la quiralidad (CISS), mejorando las aplicaciones optoelectrónicas.
Área de la Ciencia:
- Productos electrónicos orgánicos
- La fotoquímica
- Ciencias de los materiales
Sus antecedentes:
- Los excitones triplet en los cocristales donantes-aceptantes orgánicos son cruciales para la energía solar, la optoelectrónica y la información cuántica.
- La selectividad de espín inducida por quiralidad (CISS) sugiere que la quiralidad puede influir en la formación de excitones tripletos.
Objetivo del estudio:
- Investigar el impacto de un aceptador de electrones quiral en la dinámica de transferencia de carga y la formación de excitones triplet.
- Para comparar el rendimiento de excitones triplet en cocristales con aceptores achirales versus quirales.
Principales métodos:
- Síntesis de cocristales de donante-aceptor utilizando donante de coroneno y aceptores de perileno bis (dicarboximida) aciral/quiral.
- Difracción de rayos X para el análisis estructural.
- Microscopía de absorción transitoria para la transferencia de carga y la dinámica del excitón triple.
- Espectroscopia de resonancia paramagnética de electrones con resolución de tiempo para el mecanismo de formación de excitones.
Principales resultados:
- Los cocristales con aceptores quirales exhibieron rendimientos de excitones triplet significativamente más altos (51-50%) en comparación con los aceptores achirales (38%).
- Los estados de transferencia de carga se formaron rápidamente (<0,3 ps), seguidos por la formación de excitones triplet (∼100 ps).
- Se confirmó que los excitones triplet se forman a través del cruce intersistémico de transferencia de carga en la órbita de giro.
Conclusiones:
- La selectividad de espín inducida por quiralidad (CISS) mejora la formación de excitones triplet en cocristales orgánicos.
- Los aceptores quirales aumentan los rendimientos de excitones triplet, ofreciendo potencial para mejorar el rendimiento del dispositivo optoelectrónico.
- La similitud estructural de los cocristales valida el CISS como el factor principal que influye en el rendimiento de los tripletes.
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