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Efecto Hall cuántico fraccionario en semiconductores moleculares orgánicos
1Bell Laboratories, Lucent Technologies, 600 Mountain Avenue, Murray Hill, NJ 07974, USA.
Science (New York, N.Y.)
|July 6, 2000
Resumen
Los semiconductores orgánicos de alta calidad lograron una alta movilidad del portador de carga en nuevos dispositivos. Estos materiales exhibieron fenómenos cuánticos, incluidos estados Hall cuánticos fraccionarios, allanando el camino para la electrónica avanzada.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Física de la materia condensada Física de la materia condensada
- Electrónica orgánica y electrónica orgánica.
Sus antecedentes:
- Los semiconductores moleculares orgánicos ofrecen potencial para nuevas aplicaciones electrónicas.
- Lograr una alta movilidad del portador de carga y observar los fenómenos cuánticos en estos materiales es crucial para el avance del dispositivo.
Objetivo del estudio:
- Para investigar las propiedades electrónicas de los cristales de tetraceno y pentaceno de alta calidad.
- Para fabricar y caracterizar los dispositivos de metal- aislador-semiconductor (MIS) que utilizan estos semiconductores orgánicos.
- Para explorar la manifestación de los fenómenos cuánticos en estos transistores orgánicos de efecto de campo.
Principales métodos:
- Preparación de cristales simples de tetraceno y pentaceno de alta calidad.
- Fabricación de estructuras de metal- aislante-semiconductor (MIS, por sus siglas en inglés).
- Caracterización eléctrica del rendimiento del dispositivo, incluyendo mediciones de movilidad.
- Investigación de las oscilaciones de Shubnikov-de Haas y los efectos cuánticos Hall.
Principales resultados:
- Se han logrado movilidades de orificios y electrones superiores a 10^4 cm^2/Vs en dispositivos MIS.
- Comportamiento de efecto de campo ambipolar demostrado con concentración de portador controlada por la tensión de la puerta.
- Se observaron oscilaciones de Shubnikov-de Haas bien definidas y mesetas de Hall cuantizadas a densidades de portadores 2D de 10^11 cm^-2.
- Se han reportado estados Hall cuánticos fraccionados en cristales de tetraceno a temperaturas de hasta ~2 Kelvin.
Conclusiones:
- Los semiconductores orgánicos de alta calidad pueden apoyar la movilidad de cargadores de alta carga.
- Los transistores de efecto de campo orgánico pueden exhibir fenómenos cuánticos complejos, incluidos los estados Hall cuánticos fraccionarios.
- Estos hallazgos destacan el potencial de los materiales orgánicos para aplicaciones electrónicas y cuánticas avanzadas.
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