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Ferroelectricidad en heterobilares no retorcidos de dicalcogenuros de metales de transición
Lukas Rogée1, Lvjin Wang2, Yi Zhang1
1Department of Applied Physics, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, P. R. China.
Science (New York, N.Y.)
|May 26, 2022
Resumen
Los dispositivos ferroeléctricos y piezoeléctricos ultrafinos están habilitados por los nuevos heterobilares de disulfuro de molibdeno / disulfuro de tungsteno (MoS / WS). Estos materiales exhiben propiedades significativas fuera del plano, allanando el camino para aplicaciones electrónicas avanzadas.
Área de la Ciencia:
- Ciencias de los materiales
- Física de la materia condensada
- Nanotecnología
Sus antecedentes:
- Los materiales bidimensionales (2D) son cruciales para la electrónica de próxima generación.
- Las propiedades ferroeléctricas y piezoeléctricas fuera de plano (OOP) son esenciales para los dispositivos ultrafinos.
- Los materiales 2D existentes a menudo carecen de respuestas ferroeléctricas y piezoeléctricas OOP robustas.
Objetivo del estudio:
- Investigar el potencial de los heterobiladores MoS2/WS2 para la ferroelectricidad y la piezoelectricidad OOP.
- Demostrar la síntesis de estos heterobilares utilizando métodos escalables.
- Para caracterizar sus propiedades piezoeléctricas y el rendimiento del dispositivo.
Principales métodos:
- Deposición de vapor químico escalable en un solo paso (CVD) para la síntesis de heterobilares epitaxiales de MoS2/WS2.
- Medición de las constantes piezoeléctricas fuera del plano (d33).
- Fabricación y caracterización de los dispositivos de unión de túnel ferroeléctrico (FTJ).
- Cálculos de la teoría funcional de la densidad (DFT).
Principales resultados:
- Se ha demostrado una inesperada ferroelectricidad y piezoelectricidad OOP en heterobilares no retorcidos y proporcionados MoS2/WS2.
- Logró d33 constantes piezoeléctricas de 1.95 2.09 pm/V, aproximadamente seis veces más grandes que la monocapa In2 Se3.
- Mostró una modulación de tres órdenes de magnitud de la corriente de túnel en dispositivos FTJ mediante el cambio de polarización.
- DFT confirmó que la ruptura de simetría y el deslizamiento entre capas son clave para estas propiedades.
Conclusiones:
- Los heterobilayers no retorcidos y proporcionados de MoS2/WS2 son candidatos prometedores para dispositivos ferroelectrónicos y piezoelectrónicos ultrafinos.
- La síntesis de CVD escalable permite la fabricación práctica de estos materiales.
- Los efectos ferroeléctricos y piezoeléctricos OOP observados abren nuevas vías para nuevas funcionalidades electrónicas.
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