Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 98: Electronic Structure Theory

HL 98.8: Vortrag

Freitag, 30. März 2012, 11:30–11:45, EW 202

First-principles simulations of catalytic effects of the gold nanoparticle on the GaAs nanowire growth — •Yaojun Du, Peter Kratzer, Sung Sakong, and Volker Pankoke — Fakultät für Physik and Center for Nanointergration

The interface between an Au nanoparticle and a GaAs nanowire can facilitate the nanowire growth due to a segregation of materials to the interface. Previous experimental studies have suggested that an Au nanoparticle alloyed with Ga atoms can supply Ga atoms to the interfacial growth zone. On the other hand, an Au nanoparticle can also absorb As₂ from the vapor phase during molecular beam epitaxy. This allows for a continuous supply of gallium and arsenic which is necessary for a GaAs nanowire growth. Employing density functional theory approaches, we have shown that an Au particle that can alloy with Ga atoms to form a stable surface is capable of catalytically dissociating As₂ impinging from the vapor phase. Moreover, relatively stable As-Ga species can form on the AuGa surface which could build up an As-Ga supply for growth at the interface. We are investigating the As diffusion within GaAs bulk crystal structures and along the interface between an Au nanoparticle and a GaAs nanowire. This should allow us to gain full insight on catalytic effects of the gold nanoparticle on the GaAs nanowire growth.