Precursor flow rate manipulation for the controlled fabrication of twin-free GaAs nanowires on silicon substrates

Date

2012

Authors

Kang, Jung-Hyun
Gao, Qiang
Parkinson, Patrick
Joyce, Hannah J
Jagadish, Chennupati
Guo, Y.
Xu, Hong-Yi
Zou, Jin
Kim, Yong
Tan, Hark Hoe

Journal Title

Journal ISSN

Volume Title

Publisher

Institute of Physics Publishing

Abstract

Vertically oriented GaAs nanowires (NWs) are grown on Si(111) substrates using metal-organic chemical vapor deposition. Controlled epitaxial growth along the 111 direction is demonstrated following the deposition of thin GaAs buffer layers and the elimination of structural defects, such as twin defects and stacking faults, is found for high growth rates. By systematically manipulating the AsH 3 (group-V) and TMGa (group-III) precursor flow rates, it is found that the TMGa flow rate has the most significant effect on the nanowire quality. After capping the minimal tapering and twin-free GaAs NWs with an AlGaAs shell, long exciton lifetimes (over 700ps) are obtained for high TMGa flow rate samples. It is observed that the Ga adatom concentration significantly affects the growth of GaAs NWs, with a high concentration and rapid growth leading to desirable characteristics for optoelectronic nanowire device applications including improved morphology, crystal structure and optical performance.

Description

Keywords

Keywords: Exciton lifetime; GaAs; High concentration; High growth rate; Nanowire devices; Optical performance; Precursor flow rates; Rapid growth; Si(111) substrate; Silicon substrates; Structural defect; Twin-free; Aluminum gallium arsenide; Epitaxial growth; Flow

Citation

Source

Nanotechnology

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

DOI

10.1088/0957-4484/23/41/415702

Restricted until

2037-12-31