Dimension Control of Hexagonal SiGe Single Branched Nanowires.

Hexagonal SiGe, with its direct band gap, holds promising light-emission properties and potential for advanced optoelectronic applications. The growth of this material has been achieved as nanowires, within core-shell or multibranch trunk structures. However, core-shell designs are limited to radial growth, restricting the axial dimensional control, while multibranch structures lack growth precision, reducing their practical applicability. Here, we introduce a novel technique to grow hexagonal SiGe as single-branched nanowires, achieving unprecedented control over dimension and morphology. The branch diameter is precisely tuned by adjusting the trunk diameter, leveraging the use of the same Au catalyst particle throughout both trunk and branch growth. We investigate the growth rate and its diameter dependency within the Gibbs-Thomson framework, providing valuable insights into growth dynamics. This innovative method opens new opportunities for advanced studies on hexagonal SiGe, paving the way for developing next-generation quantum devices.