Identification of an Intrinsic Source of Doping Inhomogeneity in Vapor–Liquid–Solid-Grown Nanowires

Journal Article · Wed Jan 09 04:00:00 EST 2013 · Nano Letters, 13(1):199-206

DOI:https://doi.org/10.1021/nl3038695· OSTI ID:1177364

Connell, Justin G.; Yoon, KunHo; Perea, Daniel E.; Schwalbach, Edwin J.; Voorhees, Peter W.; Lauhon, Lincoln

The vapor-liquid-solid (VLS) process of semiconductor nanowire growth is an attractive approach to low-dimensional materials and heterostructures because it provides a mechanism to modulate, in situ, nanowire composition and doping, but the ultimate limits on doping control are ultimately dictated by the growth process itself. Under widely used conditions for the chemical vapor deposition growth of Si and Ge nanowires from a Au catalyst droplet, we find that dopants incorporated from the liquid are not uniformly distributed. Specifically, atom probe tomographic analysis revealed up to 100-fold enhancements in dopant concentration near the VLS tri-junction in both B-doped Si and P-doped Ge nanowires. We hypothesize that radial and azimuthal inhomogeneities arise from a faceted liquid-solid interface present during nanowire growth, and we present a simple model to account for the distribution. As the same segregation behavior was observed in two distinct semiconductors with different dopants, the observed inhomogeneity is likely to be present in other VLS grown nanowires.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1177364
• Report Number(s): PNNL-SA-98432; 47607; KP1704020
• Journal Information: Nano Letters, 13(1):199-206, Journal Name: Nano Letters, 13(1):199-206
• Country of Publication: United States
• Language: English

Related Subjects

Environmental Molecular Sciences Laboratory