Confinement and surface effects in B and P doping of silicon nanowires
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
20/10/2012
20/10/2012
2008
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Resumo |
Several experimental groups have achieved effective n- and p-type doping of silicon nanowires (SiNWs). However, theoretical analyses on ultrathin SiNWs suggest that dopants tend to segregate to their surfaces, where they would combine with defects such as dangling bonds (DB), becoming electronically inactive. Using fully ab initio calculations, we show that the differences in formation energies among surface and core substitutional sites decrease rapidly as the diameters of the wires increase, indicating that the dopants will be uniformly distributed. Moreover, occurrence of the electronically inactive impurity/DB complex rapidly becomes less frequent for NWs of larger diameters. We also show that the high confinement in the ultrathin SiNWs causes the impurity levels to be deeper than in the silicon bulk, but our results indicate that for NWs of diameters larger than approximately 3 nm the impurity levels recover bulk characteristics. Finally, we show that different surfaces will lead to different dopant properties in the gap. |
Identificador |
NANO LETTERS, v.8, n.7, p.1866-1871, 2008 1530-6984 http://producao.usp.br/handle/BDPI/29428 10.1021/nl080403d |
Idioma(s) |
eng |
Publicador |
AMER CHEMICAL SOC |
Relação |
Nano Letters |
Direitos |
restrictedAccess Copyright AMER CHEMICAL SOC |
Palavras-Chave | #SEMICONDUCTOR NANOWIRES #LARGE SYSTEMS #TRANSISTORS #ENERGIES #Chemistry, Multidisciplinary #Nanoscience & Nanotechnology #Materials Science, Multidisciplinary |
Tipo |
article original article publishedVersion |