NH₃ molecular doping of silicon nanowires grown along the [112], [110], [001], and [111] orientations

The possibility that an adsorbed molecule could provide shallow electronic states that could be thermally excited has received less attention than substitutional impurities and could potentially have a high impact in the doping of silicon nanowires (SiNWs). We show that molecular-based ex-situ dopin...

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Detalles Bibliográficos
Autores: Miranda, Álvaro, Cartoixà, Xavier|||0000-0003-1905-5979, Canadell Casanova, Enric|||0000-0002-4663-5226, Rurali, Riccardo|||0000-0002-4086-4191
Tipo de recurso: artículo
Fecha de publicación:2012
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:184838
Acceso en línea:https://ddd.uab.cat/record/184838
https://dx.doi.org/urn:doi:10.1186/1556-276X-7-308
Access Level:acceso abierto
Palabra clave:Silicon nanowires
Ammonia
Molecular doping
DFT
Electronic properties
Gas sensing
Descripción
Sumario:The possibility that an adsorbed molecule could provide shallow electronic states that could be thermally excited has received less attention than substitutional impurities and could potentially have a high impact in the doping of silicon nanowires (SiNWs). We show that molecular-based ex-situ doping, where NH₃ is adsorbed at the sidewall of the SiNW, can be an alternative path to n-type doping. By means of first-principle electronic structure calculations, we show that NH₃ is a shallow donor regardless of the growth orientation of the SiNWs. Also, we discuss quantum confinement and its relation with the depth of the NH₃ doping state, showing that the widening of the bandgap makes the molecular donor level deeper, thus more difficult to activate.