Nanostructured broadband antireflection coatings on AlInP fabricated by nanoimprint lithography

We report the fabrication of moth-eye antireflection nanostructures on AlInP compound commonly used as a window layer in high-efficiency multijunction solar cells. The broadband antireflective nanostructures were fabricated by nanoimprint lithography directly on molecular beam epitaxy grown AlInP/GaAs surface. At normal incidence, the structures exhibited an average reflectivity of 2.7% measured in a spectral range 450–1650 nm. Photoluminescence measurements of the emission from GaAs substrate suggest that the optical losses associated with the moth-eye pattern are low. Nanoimprint lithography offers a cost-effective approach to fabricate broadband antireflection coatings required in III–V high-efficiency multijunction solar cells.