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Parejas aisladas estereocímicamente activas y propiedades ópticas no lineales de perovskitas multidimensionales de
Xinyu Li1, Yan Guan1, Xiaotong Li2
1Beijing National Laboratory for Molecular Science, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Journal of the American Chemical Society
|September 22, 2022
Resumen
Este estudio explora las nuevas perovskitas de estaño y yoduro de germanio 2D, revelando sus propiedades semiconductoras sintonizables y su potencial como alternativas sin plomo para la optoelectrónica debido a la actividad única de electrones en pares.
Área de la Ciencia:
- Ciencias de los materiales
- Química del estado sólido
- Optoelectrónica y sus derivados
Sus antecedentes:
- Las perovskitas de halogenuros metálicos bidimensionales (2D) son semiconductores sintonizables, con investigaciones previas centradas en sistemas basados en plomo (Pb).
- Las perovskitas 2D basadas en estaño (Sn) y germanio (Ge) siguen siendo poco exploradas, a pesar del potencial para una química estructural diversa y propiedades únicas de electrones de pares solitarios polarizables.
Objetivo del estudio:
- Sintetizar y caracterizar nuevas perovskitas de estaño y yoduro de germanio en 2D.
- Investigar las relaciones estructura-propiedad, particularmente la influencia de la actividad estereocímica de pares solitarios en la estructura cristalina, el semiconductor y las propiedades ópticas no lineales.
- Evaluar estos materiales como posibles alternativas sin plomo para aplicaciones optoelectrónicas.
Principales métodos:
- Síntesis de perovskitas 2D de yoduro de estaño (BA) 2 y 2D de perovskitas de yoduro de germanio (BA) 2, donde BA = n-butilamonio y A = varios cationes orgánicos.
- Análisis estructural y comparación con las contrapartes basadas en Pb.
- Caracterización de las propiedades semiconductoras (bandgap, interacciones portador-fonón) y las propiedades ópticas no lineales (segunda generación armónica, absorción de dos fotones).
Principales resultados:
- Correlaciones establecidas entre la actividad de pares solitarios, la estructura cristalina y las propiedades del material.
- Se observó un aumento de la fuerza de interacción portador-fonón con una mayor actividad de pareja solitaria, lo que lleva a una cola de fotoluminiscencia de baja energía más prominente.
- Demostró una fuerte generación de segundo armónico (~10 pm V-1) en (BA) I7, superando significativamente a los análogos Sn y Pb.
- Coeficientes de absorción de dos fotones de tercer orden reportados (∼10 cm MW-1) para (BA) 2, que son más grandes que las contrapartes Pb y los semiconductores tradicionales.
Conclusiones:
- La actividad de pares solitarios es un factor clave que vincula la composición y las propiedades físicas en las perovskitas halogenadas 2D.
- Las perovskitas de estaño 2D y yoduro de germanio presentan propiedades ópticas no lineales prometedoras.
- Estas perovskitas 2D basadas en Sn y Ge representan alternativas viables sin plomo para dispositivos optoelectrónicos no lineales avanzados.
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