Microwell-Directed Self-Assembly of Vertical Nanowire Arrays

作者:Kirby David J*; Smith Benjamin D; Keating Christine D
来源:Particle & Particle Systems Characterization, 2014, 31(4): 492-499.
DOI:10.1002/ppsc.201300260

摘要

Vertical arrays of anisotropic particles are desired for many applications including solar cells, battery electrodes, and lasers. Partially etched nano-wires (PENs) are hybrid silica nanotube/nanowires with partial metallic cores. These particles spontaneously form vertical arrays in which on average 70% of the particles are oriented perpendicular to the underlying substrate. Here, we perform PEN self-assembly on lithographically prepared substrates patterned with square microwells having dimensions comparable to the length of the particles. Particle self-assembly is observed both in the microwells and on the intervening surfaces. PENs both directly deposit into a well and diffuse across the surface between microwells until falling into a well. Assembly occurs as the local concentration of PENs in a well increases by these two mechanisms. Microwells provide a way to control array location on a surface and improve standing percentages up to 100% when the edge dimensions are decreased to a size approximately equal to the nanowire length. Micro-wells also protect against array disruption during sample drying.

  • 出版日期2014-4