Doping GaP Core-Shell Nanowire pn-Junctions: A Study by Off-Axis Electron Holography

作者：Yazdi Sadegh^*; Berg Alexander; Borgstrom Magnus T; Kasama Takeshi; Beleggia Marco; Samuelson Lars; Wagner Jakob B

来源：Small, 2015, 11(22): 2687-2695.

DOI：10.1002/smll.201403361

• core-shell nanowires
• nanowires
• doping
• electrostatic potential
• potential maps
• gallium phosphide
• electron holography

The doping process in GaP core-shell nanowire pn-junctions using different precursors is evaluated by mapping the nanowires' electrostatic potential distribution by means of off-axis electron holography. Three precursors, triethyltin (TESn), ditertiarybutylselenide, and silane are investigated for n-type doping of nanowire shells; among them, TESn is shown to be the most efficient precursor. Off-axis electron holography reveals higher electrostatic potentials in the regions of nanowire cores grown by the vapor-liquid-solid (VLS) mechanism (axial growth) than the regions grown parasitically by the vapor-solid (VS) mechanism (radial growth), attributed to different incorporation efficiency between VLS and VS of unintentional p-type carbon doping originating from the trimethylgallium precursor. This study shows that off-axis electron holography of doped nanowires is unique in terms of the ability to map the electrostatic potential and thereby the active dopant distribution with high spatial resolution.

• 出版日期2015-6-10