Nanoroughness-induced antireflection and haze effects in opaque systems

How to make a material antireflective without changing its high refraction index? Achieving antireflection in high-refractive-index materials poses challenges due to their high reflectivity (Fresnel equations). Based on theory with new boundary conditions, we propose modifying surface properties on a nanoscale to tackle this. Our study on weakly rough opaque surfaces reveals significant changes in specular and diffuse scattering, predicting antireflection where roughness matches light penetration depth. Experimental validation on nanoroughened Si films (at wavelengths 300 to 400 nm) supports our findings. We also analyze angular and polarization dependences of nanoroughness-induced haze, showing predominant <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mi>p</a:mi></a:math> polarization and minimal haze at nanoscale, yet impactful specular reflection reduction. Published by the American Physical Society 2024