Fundamental Insights into Nanowire Diameter Modulation and the Liquid/Solid Interface

• Published in: Nano letters 2013-01, Vol.13 (1), p.226-232
• Main Authors: Crawford, Sam, Lim, Sung Keun, Gradečak, Silvija
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Devices; Electronics; Exact sciences and technology; Gallium nitrides; Liquids; Materials science; Modulation; Molecular electronics, nanoelectronics; Morphology; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanowires; Physics; Quantum wires; Seeds; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Solid-fluid interfaces; Surface energy; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Three dimensional; Wetting
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl3039019

Controlled modulation of diameter along the axis of nanowires can enhance nanowire-based device functionality, but the potential for achieving such structures with arbitrary diameter ratios has not been explored. Here, we use a theoretical approach that considers changes in the volume, wetting angle, and three-dimensional morphology of seed particles during nanowire growth to understand and guide nanowire diameter modulation. We use our experimental results from diameter-modulated InN and GaN nanowires and extend our analysis to consider the potential and limitations for diameter modulation in other materials systems. We show that significant diameter modulations can be promoted for seed materials that enable substantial compositional and surface energy changes. Furthermore, we apply our model to provide insights into the morphology of the liquid/solid interface. Our approach can be used to understand and guide nanowire diameter modulation, as well as probe fundamental phenomena during nanowire growth.