Perturbation of Au-assisted planar GaAs nanowire growth by p-type dopant impurities

Abstract

III-V compound semiconductor nanowires (NWs), with their direct bandgaps and high mobilities, have been shown to be promising materials for many applications including solar cells, light emitting diodes, transistors, and lasers. Self-aligned, twin-plane-defect free, planar GaAs NWs can be grown by metalorganic chemical vapor deposition (MOCVD) through the Au-assisted vapor-liquid-solid mechanism. In this report, <110> planar GaAs NW growth on GaAs (100) substrates is perturbed by introducing common p-type dopant impurities, zinc (Zn) or carbon (C), and characterized structurally and electrically. The implications of the results on planar NW growth and doping mechanism are discussed.

Investigation of p-type InAs nanowires grown via Au-assisted and self-assembled methods

“…For the VLS-grown NW, the electrical resistance decreases from approximately 150 to 100 kΩ toward the NW's tip. Previous studies on p-type doping of VLS-grown NWs reported an accumulation of Zn impurities in the Au seed [10,15]. This indicates that even though the DEZn constantly flows in the reactor during the growth, the Zn doping impurities increasingly incorporate into the NWs through the Au seed.…”

“…The incorporation of p-type dopants into VLS-grown III-V NWs, however, can lead to strong kinking or perturbation in the NW [10,15]. Furthermore, the VLS-grown InAs NWs are expected to have a large variation in the doping concentration along the NW length for two main reasons: (1) different incorporation rates of the dopant through the metal seed and the NW side facets [11] and (2) delayed incorporation of the p-type dopants from the metal seed during the growth process [15]. We have recently demonstrated the self-assembled growth of III-V NWs [16].…”

Vapor-Liquid-Solid Growth of Semiconductor Nanowires

“…Although for Ge and many other VLS nanowires, it appears that most dopants reside in the thin epitaxial layers that form on the nanowire sidewalls due to the VPE growth [137,153], it has been confirmed that Zn incorporates primarily through the VLS growth in vertical [139] and planar [157] GaAs VLS nanowires. Although for Ge and many other VLS nanowires, it appears that most dopants reside in the thin epitaxial layers that form on the nanowire sidewalls due to the VPE growth [137,153], it has been confirmed that Zn incorporates primarily through the VLS growth in vertical [139] and planar [157] GaAs VLS nanowires.…”

“…The formation of twinning superlattices (TSLs) induced by p-type dopants has been reported in vertical nanowires [102,103,158,159], as well as in planar GaAs nanowires, which are otherwise free of twin-plane defects [157]. The formation of twinning superlattices (TSLs) induced by p-type dopants has been reported in vertical nanowires [102,103,158,159], as well as in planar GaAs nanowires, which are otherwise free of twin-plane defects [157].…”

Mechanism of periodic height variations along self-aligned VLS-grown planar nanostructures

“…Nanostructures possessing non-monotonous morphological variations along the growth direction are offering new avenues for device engineering, with periodic dimensional changes 13,16,20 of particular interest due to novel quantum confinement effects. [21][22][23][24] Moreover, the formation of preferentially orientated structures 25 are developed in parallel with advancing technological aims to employ bottom-up fabrication techniques.…”