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Crecimiento epitaxial robusto de las heteroestructuras bidimensionales, las multiheteroestructuras y las superredes
Zhengwei Zhang1, Peng Chen1,2, Xidong Duan1
1State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
Science (New York, N.Y.)
|August 5, 2017
Resumen
Los investigadores desarrollaron un nuevo método para el cultivo de diversas heteroestructuras de cristales atómicos bidimensionales (2D), multiheteroestructuras y superredes. Esta técnica garantiza un crecimiento epitaxial robusto, bloque por bloque, con un control espacial preciso y interfaces nítidas.
Área de la Ciencia:
- Ciencias de los materiales
- Nanotecnología
- Física del estado sólido
Sus antecedentes:
- Los cristales atómicos bidimensionales (2D) ofrecen propiedades electrónicas y ópticas únicas.
- La fabricación de heteroestructuras complejas a partir de estos materiales es un desafío debido a la degradación térmica y la nucleación incontrolada.
- El control preciso de la disposición espacial de los diferentes materiales 2D es crucial para las aplicaciones de dispositivos avanzados.
Objetivo del estudio:
- Desarrollar una estrategia sintética general y robusta para crear diversas heteroestructuras laterales, multiheteroestructuras y superredes a partir de cristales atómicos 2D.
- Para permitir una modulación espacial precisa y interfaces atómicamente nítidas en conjuntos de materiales 2D complejos.
- Demostrar el potencial de estas heteroestructuras diseñadas en dispositivos electrónicos.
Principales métodos:
- Proceso de crecimiento secuencial por deposición de vapor que incorpora un flujo inverso durante la etapa de oscilación de temperatura.
- Utilizando un enfriamiento controlado para evitar la degradación térmica y la nucleación homogénea.
- Caracterización mediante cartografía Raman y fotoluminiscencia, microscopía electrónica de transmisión (TEM) y mediciones de transporte eléctrico.
Principales resultados:
- Sintetizó con éxito una amplia gama de heteroestructuras 2D (por ejemplo, WS2-WSe2, WS2-MoSe2), multiheteroestructuras (por ejemplo, WS2-WSe2-MoS2) y superredes (por ejemplo, WS2-WSe2-WS2-WSe2-WS2).
- Logrado modulación espacial controlada con precisión y interfaces atómicamente nítidas, confirmadas por TEM.
- Características del diodo bien definidas en las uniones laterales WSe2-WS2 con un alto coeficiente de rectificación de hasta 105.
Conclusiones:
- La técnica de flujo inverso desarrollada proporciona una estrategia general y altamente robusta para la fabricación de heteroestructuras complejas en 2D.
- Este método permite un control preciso de la disposición del material y la calidad de la interfaz.
- Las heteroestructuras sintetizadas exhiben propiedades electrónicas prometedoras para futuras aplicaciones de dispositivos.
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