Direct Evidences of Enhanced Ga Interdiffusion in InAs Vertically Aligned Free-Standing Nanowires

Abstract

Direct evidences of enhanced Ga interdiffusion in InAs free-standing nanowires grown at moderate temperatures by molecular beam epitaxy on GaAs (111)B are presented in this work. Scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction measurements in coplanar and grazing incidence geometries show that nominally grown InAs NWs are actually made of an In0.86Ga0.14As alloy. Unlike typical vapor-liquid-solid growth, these nanowires are formed by diffusion-induced growth combined with strong interdiffusion from substrate material. Based on the experimental results, a simple nanowire growth model accounting for the Ga interdiffusion is also presented. This growth model could be generally applicable to the molecular beam heteroepitaxy of III-V nanowires.

Electrical Properties of Polytypic Mg Doped GaAs Nanowires

“…The green line corresponds to the fitting of ⋅ −1/2 versus −1/4 plot in the Mott-VRH region using (2). The blue line corresponds to the fitting of ⋅ −1 versus −1/2 in the ES-VRH region using (3). measurements at much lower temperatures are necessary to precisely evaluate the ES-VRH transport regime.…”

“…Semiconductor nanowires (NWs) of III-V compounds [1][2][3][4][5] are promising nanostructures for optoelectronic devices applications [5,6]. However, the influence of temperature as well as the polytypism in the transport mechanisms of p-type doped III-V NWs has been barely investigated [6][7][8][9][10][11][12][13][14][15].…”

Electronic transport in p‐type Mg‐doped GaAs nanowires

“…Semiconductor nanowires (NWs) of III–V compounds such as InP and In x Ga 1− x As , are promising nanostructures for optoelectronic devices . The electronic transport mechanisms as well as the p‐type doping of GaAs NWs have been investigated .…”

Structural and optical characterization of Mg-doped GaAs nanowires grown on GaAs and Si substrates

“…[1][2][3][4] Investigations have evidenced that the formation of the WZ phase is generally favored by processes arising from the large surface-to-volume ratios of the nanowires, usually with small diameters, 5,6 and its fraction along the growth axis depends on the growth parameters. 3,7-10 III-V nanowires have been grown by several techniques, namely, molecular beam epitaxy (MBE), [11][12][13] chemical beam epitaxy (CBE), 14,15 and metalorganic chemical vapor deposition (MOCVD) 2,16 through the particle-assisted vapor-liquid-solid (VLS) 17 mechanism mainly with Au as catalyst. Despite the significant achievements obtained in the nanowires synthesis, a full understanding of the influence of the substrate on the fraction of each phase is still lacking.…”