Quantifying the Impact of Randomness on Light Scattering of Colloidal Nanopattern Array

Bottom-up fabrication of colloidal nanopattern arrays provides a scalable and cost-effective pathway toward functional photonic devices, yet the inherent randomness of self-assembly introduces defects that may impair optical performance. Here, we quantitatively assess the influence of microscopic disorder on far-field light scattering by combining dark-field measurements with momentum-space (Q-space) analysis. A theoretical model incorporating random defects in large-area arrays (>2000 nanostructures) reproduces the experimental spectra with excellent fidelity. We find that the dark-field response is dominated by peripheral disordered scatterers, while contributions from the ordered interior are negligible. Remarkably, the arrays tolerate defect probabilities up to 25% for monotype defect and 40% for mixed type defect, maintaining nearly invariant peak positions despite a ∼50% reduction in first-order diffraction intensity. Moreover, interstitial defects are shown to degrade optical fidelity more severely than vacancies and dislocations at comparable disorder levels. These results establish a quantitative foundation for defect-tolerant design in self-assembled photonic systems, addressing a central challenge for scalable, low-cost photonic device manufacturing.