Glass Flow Evolution and the Mechanism of Antireflective Nanoprotrusion Arrays in Nanoholes by Direct Thermal Imprinting

Moth-eye-mimicking nanoprotrusion arrays are typical bioinspired broadband antireflection patterns that improve the transmittance and visibility of optical devices by adjusting different geometrical parameters of nanostructures, such as diameter, height, shape, and periodic arrangement, and widely used in solar cells, electronic displays, and so on. Rapid, net-shape, less complicated, and low-cost fabrication of the glass-based moth-eye nanostructure array is a huge challenge. This work adopted the nanohole array template to transform the moth-eye nanostructures on the optical glass by hot embossing combined with ultrasonic-assisted demolding. To investigate the mode transition and filling behavior of the glass nanostructures when compressed into the nanoholes, we conducted a series of hot embossing tests with various processing parameters and characterized the geometrical morphology of the glass-based nanostructure array, such as height and shape. In these tests, surface defects such as nanocracks will occur when inappropriate processing parameters were applied and we evaluated the transmittance performance of defective and fine glass nanostructures and surface with no nanostructures to reveal the effect of nanostructures with different levels of quality on antireflection. This work provides an effective and environmental-friendly method for the fabrication of moth-eye nanostructure arrays with an improved antireflection performance.