Atomic-Scale Characterization of Planar Selective-Area-Grown InAs/InGaAs Nanowires

Abstract

Atomic-scale information about the structural and compositional properties of novel semiconductor nanowires is essential to tailoring their properties for specific applications, but characterization at this length scale remains a challenging task. Here, quasi-1D InAs/InGaAs semiconductor nanowire arrays were grown by selective area epitaxy (SAE) using molecular beam epitaxy (MBE), and their subsequent properties were analyzed by a combination of atom probe tomography (APT) and aberrationcorrected transmission electron microscopy (TEM). Results revealed the chemical composition of the outermost thin InAs layer, a fine variation in the indium content at the InAs/InGaAs interface, and lightly incorporated element tracing. The results highlight the importance of correlative microscopy approaches in revealing complex nanoscale structures, with TEM being uniquely suited to interrogating the crystallography of InGaAs NWs, whereas APT is capable of three-dimensional (3D) elemental mapping, revealing the subtle compositional variation near the boundary region. This work demonstrates a detailed pathway for the nanoscale structural assessment of novel one-dimensional (1D) nanomaterials.

Nucleation-Dependent Surface Diffusion in Anisotropic Growth of III–V Nanostructures

“…Pitch-dependent re-emission of group III atoms from dielectric mask in the SAE process , can also be considered. Planar growth of VLS or SAE NWs − can be described using a similar approach. The Gibbs–Thomson effect in very thin VLS NWs and possible desorption of group III adatoms from a catalyst droplet or flat top facet can be included in the model.…”

Efficient Synthesis of Highly Crystalline One-Dimensional CrCl3 Atomic Chains with a Spin Glass State

“…The synthesis of 1D magnetic chains is an essential precondition for the investigation of their physical properties. Nevertheless, the reduction of size down to atomic chains, which invariably leads to curling and instability, makes the synthesis and physical characterization quite challenging. − The 1D materials obtained by the solution method and mechanical exfoliation are usually dozens of nanometers in diameter, and prone to contaminant residues, making it hardly meet the demand of high quality 1D chains. − Although molecular beam epitaxy (MBE) can satisfy the size constraint, it tends to require special substrates, making device processing difficult and unfavorable for practical applications. − …”