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Moléculas orgánicas optoelectrónicamente activas basadas en carborano: materiales huéspedes de la brecha de banda
Kyung-Ryang Wee1, Yang-Jin Cho, Soyeong Jeong
1Department of Advanced Materials Chemistry, Korea University, 2511 Sejong-ro, Sejong 339-700, South Korea.
Journal of the American Chemical Society
|October 13, 2012
Resumen
Los nuevos materiales basados en carborano permiten diodos orgánicos emisores de luz (PHOLED, por sus siglas en inglés) de fosforescencia azul profundo eficientes. Estos anfitriones de carborano ofrecen una alta energía triple y estabilidad, cruciales para las aplicaciones avanzadas de PHOLED azul.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Electrónica orgánica y electrónica orgánica.
- La fotofísica es la fotofísica.
Sus antecedentes:
- Los diodos orgánicos emisores de luz de fosforescencia azul profundo (PHOLED) son cruciales para las pantallas y la iluminación a todo color.
- Desarrollar materiales huéspedes estables y eficientes para los PHOLED azules sigue siendo un desafío significativo.
Objetivo del estudio:
- Para sintetizar y caracterizar nuevos materiales anfitriones basados en carborano para PHOLEDs de color azul profundo.
- Investigar las relaciones estructura-propiedad entre los isómeros de carborano y su rendimiento en PHOLEDs.
Principales métodos:
- Síntesis de derivados de orto-, meta- y para-carborano con unidades de fenilo carbazolílico (o-Cb, m-Cb, p-Cb).
- Caracterización fotofísica que incluye mediciones de energía triple (T(1)) y temperatura de transición de vidrio (T(g)).
- Fabricación de dispositivos y pruebas de PHOLED utilizando p-Cb como material huésped.
- Cálculos de la Teoría Funcional de Densidad (DFT) para comprender las propiedades electrónicas.
Principales resultados:
- Los huéspedes basados en carborano (m-Cb, p-Cb) exhibieron una alta energía tripleta (3,1 eV) y estructuras no conjugadas, adecuadas para PHOLED azules.
- Las altas temperaturas de transición de vidrio (132 °C para m-Cb, 164 °C para p-Cb) indican una buena estabilidad térmica.
- p-Cb demostró una alta movilidad de agujero (1.1 × 10(-3) cm((2) / V s)) y se utilizó con éxito en un PHOLED. azul profundo.
- El PHOLED fabricado basado en p-Cb logró una alta eficiencia cuántica externa del 15,3% con coordenadas CIE (0,15, 0,24).
Conclusiones:
- Las estructuras de carborano proporcionan propiedades fotofísicas ventajosas, incluida una alta energía triple, esencial para los PHOLED azules profundos.
- La naturaleza no conjugada y la alta estabilidad térmica de m-Cb y p-Cb los convierten en materiales anfitriones prometedores.
- p-Cb demuestra un excelente rendimiento como material huésped para PHOLED azules profundos eficientes y estables.
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