Growth Control of In-Plane Silicon Nanowires via Catalyst Size-Dependent Laser Heating for High-Performance Electronics

The in-plane growth of high-quality crystalline silicon nanowires (SiNWs) guided by laser-heated metal catalysts provides a solid one-dimensional channel material for the integration of high-performance Si-based electronics, while the growth control of these SiNWs remains an unexplored problem. In this study, we demonstrate that the laser-heated growth of IPSLS SiNWs can be modulated by the diameter of leading catalysts. The large catalysts with a diameter of ∼220 nm were directly heated under continuous laser illumination by a typical selected laser-droplet-heating mode, which resulted in the rapid growth of high-quality SiNWs with a large diameter of 166 ± 27 nm. Conversely, the small catalysts (diameter of <130 nm) can only be activated by the underlying silicon substrate heated under laser illumination, allowing the rapid growth of thin SiNWs of 74 ± 9 nm within 30 s. The different growth modes can be explained by a size-dependent heating theory of nanoscale catalysts with laser illumination. This study proposes a comprehensive understanding of the growth and diameter control of in-plane SiNWs under laser illumination, providing high-quality channel arrays for the construction of Si-based electronics.