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Estudio de la formación de vidrio y la cinética de la cristalización en una perovskita de haluro metálico 2D
Akash Singh1,2, Yongshin Kim1,2, Reece Henry3
1Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, United States.
Journal of the American Chemical Society
|August 8, 2023
Resumen
Los investigadores descubrieron nuevas perovskitas de haluro metálico vítreo (MHP) con cinética de cristalización ajustable. Esto expande las aplicaciones de MHP en áreas como los metamateriales y la computación neuromórfica.
Área de la Ciencia:
- Ciencias de los materiales
- Química del estado sólido
Sus antecedentes:
- Las perovskitas cristalinas de haluro metálico 2D (MHP) son semiconductores establecidos para la energía fotovoltaica, emisores y sensores.
- El reciente descubrimiento de la formación de vidrio en los MHP permite el cambio reversible entre propiedades optoelectrónicas distintas.
- Los MHP vidriosos existentes exhiben una lenta transformación de cristal de vidrio, lo que requiere materiales con composiciones y cinética variadas.
Objetivo del estudio:
- Para reportar la formación de vidrio en un nuevo MHP de baja temperatura de fusión, 1-MeHa2PbI4.
- Ampliar el rango de composición de la formación de vidrio MHP, incluidas las variaciones orgánicas y halogenadas.
- Investigar la cinética de la transformación vidrio-cristal y los factores que estabilizan el estado vítreo.
Principales métodos:
- Calorimetría ultrarrápida para confirmar la formación de vidrio.
- Modelado cinético, termodinámico y reológico para estudiar la cinética de la transformación.
- Análisis de las energías de activación, las tasas de crecimiento de los cristales, los gráficos de Angell y el índice de fragilidad.
Principales resultados:
- La formación de vidrio se logra en 1-MeHa2PbI4, extendiendo la formación de vidrio MHP a los componentes orgánicos alifáticos ramificados y a los haluros de yoduro.
- Elucidación del papel de la pérdida de ioduro orgánico y de hidrógeno en la estabilización del estado vítreo.
- Inferida velocidad de crecimiento de cristales rápidos de 0,21 m/s para 1-MeHa2PbI4.
Conclusiones:
- 1-MeHa2PbI4 representa una nueva clase de MHP vidriosos con cinética de cristalización ajustable.
- La rápida tasa de crecimiento de los cristales sugiere el potencial para aplicaciones en metamateriales, memoria no volátil y dispositivos informáticos.
- Este trabajo amplía el alcance de la formación de vidrio MHP y sus aplicaciones potenciales.
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