Anti-reflective engineering via moth-eye-inspired nanostructures: fundamental principles, fabrications, and applications

Anti-reflection has drawn increasing attention due to its promising applications such as photovoltaics, glazing windows, radiative cooling and other optical devices. Bioinspired moth-eye nanostructures, characterized by sub-wavelength protrusions, have emerged as an effective solution for realizing near-zero reflection across a broad spectral range. By mimicking a gradient refractive index transition, artificial structures replicate the intrinsic anti-reflective properties of natural moth eyes. This review provides an overview of recent advances in optical principles, fabrication techniques, and practical applications of moth-eye-inspired nanostructures. It begins by elucidating the fundamental optical mechanisms underlying anti-reflection by nanoscale geometries. Next, commonly employed fabrication methods are systematically categorized from both top-down and bottom-up perspectives. A detailed evaluation of these techniques is presented, focusing on key factors such as cost, scalability, accuracy, flexibility, and repeatability. This review then highlights the promising practical applications of these nanostructures in macro-engineering such as photovoltaics, smart windows, and optical devices. Finally, it discusses the current challenges and future prospects of the bioinspired anti-reflective nanostructures. By systematically summarizing sub-wavelength anti-reflective structures, this work aims to further bridge the gap between nanomaterials science and macro-scale engineering, thereby paving the way for the practical implementation of nanotechnology.