Surface functionalization of Ag-doped zirconium oxide layers for molecular alignment

Abstract

Ag-doped ZrO films were fabricated using a brush-based solution-coating process that integrated conventional film formation with alignment layer treatment in a single step. The films were doped with Ag at concentrations of 0, 10, and 20 wt%. Shear stress generated by brush-hair movements induced anisotropic micro- and nanogroove structures on the film surface, facilitating uniform liquid crystal (LC) alignment through geometric constraints. The LC alignment state was confirmed by polarized optical microscopy. The Ag-doped ZrO films exhibited a high polar anchoring energy of 1.82 × 10⁻³ J m⁻² and minimal hysteresis, indicating a weak image-sticking effect. Additionally, these films demonstrated an optical transmittance of 83.5 %, making them suitable for optoelectronic applications. Overall, Ag doping enhances the functionality of ZrO films as uniform LC alignment layers and broadens their potential for LC device applications.