TY - JOUR

T1 - Impact of droplet composition on the nucleation rate and morphology of vapor-liquid-solid GeSn nanowires

AU - Hijazi, Hadi

AU - Zeghouane, Mohammed

AU - Bassani, Franck

AU - Gentile, Pascal

AU - Salem, Bassem

AU - Dubrovskii, Vladimir G.

PY - 2020/10/2

Y1 - 2020/10/2

N2 - It is well-known that the chemical potential which drives the vapor-liquid-solid growth of semiconductor nanowires is strongly affected by the liquid phase composition. Here, we investigate theoretically how the droplet composition influences the nucleation of Au-catalyzed GeSn nanowires on Ge(111) and Si(111) substrates. We compare the chemical potentials in an Au-Ge-Sn catalyst droplet before and after adding Ga and/or Si atoms. It is found that the presence of these atoms enhances the nucleation rate of nanowires on both substrates. Theoretical results are compared to experimental data on GeSn nanowires grown in a hot-wall reduced pressure chemical vapor deposition reactor. It is shown that the intentional addition of Ga in the de-wetting step improves the uniformity of the nanowire dimensions and yields higher density of nanowires over Ge(111) substrates. The nanowire growth on Si(111) substrate occurs only when Ga and/or Si are added to Au droplets. These results show that controlling the composition of the catalyst droplet is crucial for improving the quality of GeSn nanowires.

AB - It is well-known that the chemical potential which drives the vapor-liquid-solid growth of semiconductor nanowires is strongly affected by the liquid phase composition. Here, we investigate theoretically how the droplet composition influences the nucleation of Au-catalyzed GeSn nanowires on Ge(111) and Si(111) substrates. We compare the chemical potentials in an Au-Ge-Sn catalyst droplet before and after adding Ga and/or Si atoms. It is found that the presence of these atoms enhances the nucleation rate of nanowires on both substrates. Theoretical results are compared to experimental data on GeSn nanowires grown in a hot-wall reduced pressure chemical vapor deposition reactor. It is shown that the intentional addition of Ga in the de-wetting step improves the uniformity of the nanowire dimensions and yields higher density of nanowires over Ge(111) substrates. The nanowire growth on Si(111) substrate occurs only when Ga and/or Si are added to Au droplets. These results show that controlling the composition of the catalyst droplet is crucial for improving the quality of GeSn nanowires.

KW - GeSn nanowires

KW - droplet composition

KW - nucleation rate

KW - vapor-liquid-solid growth

KW - PHASE

KW - SEMICONDUCTORS

KW - GROWTH

UR - http://www.scopus.com/inward/record.url?scp=85088566388&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/ac7482a6-d9e8-3d1a-8ea2-2d6b6a7c6518/

U2 - 10.1088/1361-6528/ab99f6

DO - 10.1088/1361-6528/ab99f6

M3 - Article

VL - 31

JO - Nanotechnology

JF - Nanotechnology

SN - 0957-4484

IS - 40

M1 - 405602

ER -