Self-catalyzed, pure zincblende GaAs nanowires grown on Si(111) by molecular beam epitaxy

Article

关键词: LIQUID-SOLID MECHANISM;    ZINC-BLENDE;    POLYTYPISM;   

DOI  :  10.1103/PhysRevB.82.035302

来源: SCIE

【 摘 要 】

We report on the Au-free molecular beam epitaxy growth of coherent GaAs nanowires directly on Si(111) substrates. The growth is catalyzed by liquid Ga droplets formed in the openings of a native oxide layer at the initial growth stage. Transmission electron microscopy studies demonstrate that the nanowires are single crystals having the zincblende structure along their length (apart from a thin wurtzite region directly below the Ga droplet), regardless of their diameter (70-80 nm) and the growth temperature range (560-630 degrees C). We attribute the observed phase purity to a much lower surface energy of liquid Ga than that of Au-Ga alloys, which makes triple line nucleation energetically unfavorable. The change in growth catalyst to a liquid metal with a lower energy suppresses the (more usual) formation of wurtzite nuclei on surface energetic grounds. These results can provide a distinct method for the fabrication of chemically pure and stacking-fault-free zincblende nanowires of III-V compounds on silicon.

【 授权许可】

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