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Perovskita doble de yoduro de bismuto y plata de banda directa: la influencia de dirección de la estructura de un
Manoj K Jana1, Svenja M Janke1,2, David J Dirkes3
1Department of Mechanical Engineering and Materials Science , Duke University , Durham , North Carolina 27708 , United States.
Journal of the American Chemical Society
|April 25, 2019
Resumen
Los investigadores desarrollaron una nueva perovskita doble de Ag-Bioduro sin plomo, superando los desafíos de estabilidad para aplicaciones optoelectrónicas. Este nuevo material ofrece una brecha de banda directa, allanando el camino para tecnologías avanzadas de conversión de energía solar.
Área de la Ciencia:
- Ciencias de los materiales
- Química del estado sólido
- Optoelectrónica y sus derivados
Sus antecedentes:
- Las perovskitas tridimensionales híbridas de haluro de plomo orgánico-inorgánico (HOIP) son prometedoras para la energía solar, pero se enfrentan a problemas de estabilidad y toxicidad.
- Los HOIP bidimensionales ofrecen una mayor estabilidad y capacidad de atunar, siendo las perovskitas dobles sin plomo (DP) un objetivo clave.
- Lograr DPs de yoduro metálico mixto 2D con bajos espacios de banda ha sido un desafío debido a la inestabilidad y la competencia de fases.
Objetivo del estudio:
- Para sintetizar y caracterizar la primera perovskita doble de 2D Ag-Bioduro.
- Explorar el uso de cationes orgánicos diseñados específicamente para estabilizar nuevos HOIP 2D.
- Investigar las propiedades optoelectrónicas y la estructura electrónica del nuevo material para posibles aplicaciones.
Principales métodos:
- Síntesis de un DP de Ag-Bioduro 2D modelado por cationes de oligotiofeno bifuncionalizados.
- Caracterización de la estructura y las propiedades optoelectrónicas del material, incluida la medición de la brecha de banda.
- Cálculos de la teoría funcional de la densidad híbrida (DFT) para aclarar la estructura de la banda electrónica.
Principales resultados:
- Síntesis exitosa del primer 2D Ag-Bi yoduro DP.
- Determinación experimental de una brecha de banda directa de 2,00(2) eV.
- Los cálculos de DFT confirmaron la brecha de banda directa e identificaron los estados electrónicos clave (Ag-d/I-p y Bi-p/I-p) responsables de los bordes de la banda.
Conclusiones:
- El estudio presenta un nuevo DP de 2D Ag-Bioduro libre de plomo estabilizado por cationes de oligotiofeno diseñados.
- El material exhibe propiedades de brecha de banda directa prometedoras para aplicaciones optoelectrónicas.
- Este trabajo demuestra una estrategia para acceder a HOIPs 2D previamente inaccesibles a través de un diseño de catión orgánico a medida.
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