Large-area self-assembly of silica microspheres/nanospheres by temperature-assisted dip-coating

Carlos García Núñez, William Taube Navaraj, Fengyuan Liu, Dhayalan Shakthivel, Ravinder Dahiya

Research output: Contribution to journalArticle

22 Citations (Scopus)
1 Downloads (Pure)

Abstract

This work reports a temperature-assisted dip-coating method for self-assembly of silica (SiO2) microspheres/nanospheres (SPs) as monolayers over large areas (∼cm2). The area over which self-assembled monolayers (SAMs) are formed can be controlled by tuning the suspension temperature (Ts), which allows precise control over the meniscus shape. Furthermore, the formation of periodic stripes of SAMs, with excellent dimensional control (stripe width and stripe-to-stripe spacing), is demonstrated using a suitable set of dip-coating parameters. These findings establish the role of Ts, and other parameters such as withdrawal speed (Vw), withdrawal angle (θw), and withdrawal step length (Lw). For Ts ranged between 25 and 80 °C, the morphological analysis of dip-coatings shows layered structures comprising of defective layers (25–60 °C), single layers (70 °C), and multilayers (>70 °C) owing to the variation of SP flux at the meniscus/substrate assembling interface. At Ts = 70 °C, there is an optimum Vw, approximately equal to the downshift speed of the meniscus (Vm = 1.3 μm/s), which allows the SAM formation over areas (2.25 cm2) roughly 10 times larger than reported in the literature using nanospheres. Finally, the large-area SAM is used to demonstrate the enhanced performance of antireflective coatings for photovoltaic cells and to create metal nanomesh for Si nanowire synthesis.
Original languageEnglish
Pages (from-to)3058-3068
Number of pages11
JournalACS Applied Materials & Interfaces
Volume10
Issue number3
DOIs
Publication statusPublished - 27 Dec 2017
Externally publishedYes

    Fingerprint

Keywords

  • colloidal suspensions
  • dip-coating
  • nanowires
  • photovoltaics
  • self-assembly

Cite this