Synthesis of GaAs nanowires with very small diameters and their optical properties with the radial quantum-confinement effect

Abstract

We report the synthesis and optical properties of GaAs nanowires with very small diameters. We grew the GaAs nanowires by using size-selective gold particles with nominal diameters of 5, 10, 20, 40, and 60 nm. The diameter-controlled nanowires enable us to observe blueshifts of the free exitononic emission peak from individual nanowires with decreasing gold-particle size due to the two-dimensional radial quantum-confinement effect. We also analyze the absorption and emission polarization anisotropies of these bare GaAs quantum nanowires.

III–V semiconductor nanowires for optoelectronic device applications

“…Thus quantum effects are nearly insignificant for the nanowires considered in this review. In fact, in the previous 10 years of growth, only a single paper on InP nanowires in 2001 [71] and a single paper on GaAs in 2009 [72] showed conclusive evidence for quantum confinement effects.…”

Quality of epitaxial InAs nanowires controlled by catalyst size in molecular beam epitaxy

“…(2) The In solubility in Au depends upon the nanoparticle sizes, that is, with decreasing the Au nanoparticle size, the In solubility in Au is significantly increased. 34,35 Therefore, it is anticipated that a Au catalyst with a small size tends to absorb more In atoms from the ambient vapor and leads to a higher In supersaturation, while a Au catalyst with a larger size tends to absorb less In atoms and forms a lower In supersaturation. It is generally accepted that wurtzite nucleation is favored at the high supersaturation, while with the lower supersaturation situation, zinc-blende structure is preferred.…”

Large-scale and uniform preparation of pure-phase wurtzite GaAs NWs on non-crystalline substrates

“…It is obvious that the incident light with a wavelength of <765 nm is mostly absorbed by GaAs NWs and thus has the lower reflectance intensity; this way, a bandgap ( E g ) of approximately 1.62 eV can be estimated. It is well accepted that the bandgap will be blue-shifted when the diameter of NWs is smaller than 20 nm, and a bandgap of 1.5 to 1.65 eV is usually determined in thin NWs in the literature [26-30]. As the bandgap of WZ GaAs is about 20 to 30 meV higher than that of the ZB GaAs [27,31], it is plausible that our WZ GaAs NWs have a bandgap of approximately 1.62 eV.…”