Controlling Polystyrene Particle Distribution in Colloidal Lithography For Correlated‐Disorder Structures

ABSTRACT

Photonic structures exhibiting correlated disorder have emerged as a novel and exciting research field. In particular, the ability to tailor the light scattering properties (scattering angle, wavelength range) by controlling the spatial correlations in the structure is key for efficient light‐trapping in ultrathin solar cells. In this context, colloidal lithography is a promising self‐assembly technique to fabricate ensembles of nanostructures with correlated disorder. This work focuses on the development of a simple, low‐cost, and robust colloidal lithography fabrication process based on large polystyrene particles (diameter 200 nm). The carboxyl surface functionalization, scarcely studied in the literature, is shown to prevent effectively particle aggregation and ensure the fabrication of homogeneous correlated‐disorder patterns. The ability to tune the pseudo‐period of the particle arrangement on a wide range (260–980 nm) is demonstrated by three different strategies, playing on the ionic strength of the colloidal suspension, the particle diameter and the concentration of the colloidal suspension. The correlated‐disorder character of the obtained particle arrangements is investigated by calculating the structure factor and pair correlation function from a robust statistical analysis of scanning electron microscope images.