title: Stoichiometric effect on electrical, optical, and structural properties of composition-tunable In(x)Ga(1-x)As nanowires.
abstract: Ternary InGaAs nanowires have recently attracted extensive attention due to their superior electron mobility as well as the ability to tune the band gap for technological applications ranging from high-performance electronics to high-efficiency photovoltaics. However, due to the difficulties in synthesis, there are still considerable challenges to assess the correlation among electrical, optical, and structural properties of this material system across the entire range of compositions. Here, utilizing a simple two-step growth method, we demonstrate the successful synthesis of composition and band gap tunable In(x)Ga(1-x)As alloy nanowires (average diameter = 25-30 nm) by manipulating the source powder mixture ratio and growth parameters. The lattice constants of each NW composition have been well correlated with the chemical stoichiometry and confirmed by high-resolution transmission electron microscopy and X-ray diffraction. Importantly, the as-grown NWs exhibit well-controlled surface morphology and low defect concentration without any phase segregation in all stoichiometric compositions. Moreover, it is found that the electrical nanowire device performances such as the turn-off and I(ON)/I(OFF) ratios are improved when the In concentration decreases at a cost of mobility degradation. More generally, this work suggests that a careful stoichiometric design is required for achieving optimal nanowire device performances.
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, China.
authors.forename: Jared J
authors.initials: JJ
authors.lastname: Hou
authors.forename: Fengyun
authors.initials: F
authors.lastname: Wang
authors.forename: Ning
authors.initials: N
authors.lastname: Han
authors.forename: Fei
authors.initials: F
authors.lastname: Xiu
authors.forename: SenPo
authors.initials: S
authors.lastname: Yip
authors.forename: Ming
authors.initials: M
authors.lastname: Fang
authors.forename: Hao
authors.initials: H
authors.lastname: Lin
authors.forename: Tak F
authors.initials: TF
authors.lastname: Hung
authors.forename: Johnny C
authors.initials: JC
authors.lastname: Ho
mesh_terms: D001152:Arsenicals / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D005708:Gallium / Q000737:chemistry*; D007204:Indium / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D012031:Refractometry; D013499:Surface Properties
chemical_list: D001152:Arsenicals; D046911:Macromolecular Substances; D007204:Indium; C043055:gallium arsenide; D005708:Gallium; C076773:indium arsenide