The Importance of the Radial Growth in the Faceting of Silicon Nanowires

The state of the lateral surface plays a great role in the physics of silicon nanowires Surprisingly, little is known about the phenomena that occur during growth on the facets of the wires We demonstrate here that the size and shape of the facets evolve with the exposure time and the radial growth speed Depending on the chemistry of the surface, either passivated by chlorine or decorated by gold clusters, the radial growth speed varies and the evolution of the facets is enhanced or impeded If the radial growth speed is high enough, the faceting of the wire can change from top to bottom due to the exposure time difference Three types of faceting are exposed, dodecagonal. hexagonal, and triangular An evolution model is introduced to link the different faceting structures and the possible transitions