Fabrication of hierarchical anti-reflective structures using polystyrene sphere lithography on an as-cut p-Si substrate

•Polystyrene sphere lithography and HDP dry etching to fabricate anti-reflective dual-scale structures on as-cut Si substrate.•Etching parameters, such as RF power, O2, and etching time, were adjusted to alter the surface morphology.•PS spheres were arranged uniformly in a closely-packed monolayer on the non-planar surfaces by the floating assembly method.•Experiment results show the dual-scale paraboloidal structures suppress average reflectance to below 0.5% across a spectral range of 500–1000nm.