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Búsqueda de semiconductores dispersivos y tolerantes a defectos a partir de la sustitución de elementos en materiales
Menglin Huang1, Shanshan Wang2, Tao Zhang2
1Key Laboratory of Computational Physical Sciences (MOE), and State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China.
Journal of the American Chemical Society
|March 3, 2022
Resumen
Los investigadores descubrieron una nueva estrategia para encontrar semiconductores de alto rendimiento mediante la modificación de materiales topológicos. La sustitución de elementos en aislantes topológicos crea semiconductores tolerantes a defectos con excelentes propiedades optoelectrónicas y alta movilidad del portador.
Área de la Ciencia:
- Ciencias de los materiales
- Física de la materia condensada
- Química del estado sólido
Sus antecedentes:
- Los materiales topológicos, a menudo con elementos pesados, poseen estructuras de banda invertidas y dispersivas únicas.
- La sustitución de elementos más ligeros puede transformar los materiales topológicos en semiconductores con espacios de banda ajustables, conservando propiedades deseables como la dispersión de la banda y la movilidad del portador.
- Extensa base de datos de materiales topológicos están ahora disponibles, ofreciendo un rico recurso para una mayor exploración.
Objetivo del estudio:
- Demostrar la utilidad de los materiales topológicos recientemente descubiertos como puntos de partida para la identificación de nuevos semiconductores con alta movilidad del portador y tolerancia a los defectos a través de la sustitución de elementos.
- Explorar el potencial de los semiconductores derivados para aplicaciones optoelectrónicas.
Principales métodos:
- Sustitución de elementos utilizados en tres materiales topológicos de referencia: Na3Bi, Pb2Bi2Te5 y EuCd2Sb2.
- Investigó las estructuras de banda electrónica y la estabilidad de los materiales derivados resultantes.
- Empleó métodos computacionales para predecir las propiedades de los materiales e identificar las estructuras de estado fundamental.
Principales resultados:
- Se obtuvieron con éxito varios semiconductores nuevos, incluidos Na3P, Na3As, Sn2Sb2S5 y CaZn2N2, que exhiben dispersión de banda y tolerancia a defectos.
- Estos materiales derivados son prometedores para aplicaciones optoelectrónicas.
- Para Na3P, Na3As y Na3Sb, la estructura P3̅c1, derivada del Na3Bi topológico, se identificó como el estado fundamental inesperado, superando las estructuras informadas anteriormente en estabilidad.
Conclusiones:
- El estudio valida una estrategia generalizable para descubrir semiconductores dispersivos y tolerantes a defectos mediante la modificación de materiales topológicos existentes.
- Este enfoque proporciona nuevos conocimientos sobre la física de los semiconductores y ofrece una vía para el diseño racional de materiales para la optoelectrónica.
- Los hallazgos ponen de relieve el potencial para descubrir estructuras estables del estado fundamental a través de esta estrategia de sustitución.
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