TY - JOUR
T1 - Effect of diborane on the microstructure of boron-doped silicon nanowires
AU - Pan, Ling
AU - Lew, Kok Keong
AU - Redwing, Joan M.
AU - Dickey, Elizabeth C.
N1 - Funding Information:
This work was supported by the National Science Foundation (NSF) under Grant no. DMR-0103068 and The Pennsylvania State University Materials Research Science and Engineering Center (MRSEC) for Nanoscale Science (DMR-0213623). TEM work was performed in the transmission electron microscopy facility of the Materials Characterization Laboratory at The Pennsylvania State University.
PY - 2005/4/15
Y1 - 2005/4/15
N2 - Boron-doped silicon (Si) nanowires, with nominal diameters of 80 nm, were grown via the vapor-liquid-solid (VLS) mechanism using gold (Au) as a catalyst and silane (SiH4) and diborane (B2H6) as precursors. The microstructure of the nanowires was studied by scanning electron microscopy, transmission electron microscopy and electron energy-loss spectroscopy. At lower B2H6 partial pressure and thus lower doping levels (≤1×1018 cm-3), most of the boron-doped Si nanowires exhibited high crystallinity. At higher B 2H6 partial pressure (∼2×1019 cm -3 doping level), the majority of the wires exhibited a core-shell structure with an amorphous Si shell (20-30 nm thick) surrounding a crystalline Si core. Au nanoparticles on the outer surface of the nanowires were also observed in structures grown with high B/Si gas ratios. The structural changes are believed to result from an increase in the rate of Si thin-film deposition on the outer surface of the nanowire at high B2H6 partial pressure, which produces the amorphous coating and also causes an instability at the liquid/solid interface resulting in a loss of Au during nanowire growth.
AB - Boron-doped silicon (Si) nanowires, with nominal diameters of 80 nm, were grown via the vapor-liquid-solid (VLS) mechanism using gold (Au) as a catalyst and silane (SiH4) and diborane (B2H6) as precursors. The microstructure of the nanowires was studied by scanning electron microscopy, transmission electron microscopy and electron energy-loss spectroscopy. At lower B2H6 partial pressure and thus lower doping levels (≤1×1018 cm-3), most of the boron-doped Si nanowires exhibited high crystallinity. At higher B 2H6 partial pressure (∼2×1019 cm -3 doping level), the majority of the wires exhibited a core-shell structure with an amorphous Si shell (20-30 nm thick) surrounding a crystalline Si core. Au nanoparticles on the outer surface of the nanowires were also observed in structures grown with high B/Si gas ratios. The structural changes are believed to result from an increase in the rate of Si thin-film deposition on the outer surface of the nanowire at high B2H6 partial pressure, which produces the amorphous coating and also causes an instability at the liquid/solid interface resulting in a loss of Au during nanowire growth.
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U2 - 10.1016/j.jcrysgro.2005.01.091
DO - 10.1016/j.jcrysgro.2005.01.091
M3 - Article
AN - SCOPUS:15844364599
VL - 277
SP - 428
EP - 436
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
SN - 0022-0248
IS - 1-4
ER -