Spectroscopic ellipsometry of nanostructured GaSb surfaces consisting of densely packed 80-230 nm long cones

Nanostructured GaSb surfaces are investigated and characterised by Spectroscopic Ellipsometry (SE). In particular, the parameters of a recently developed graded anisotropic effective medium model are tentatively fitted to the data recorded from surfaces of densely packed long cones (higher than 60 nm). Both single graded and double graded, anisotropic effective medium models are tested. In particular, we discuss the results from modelling the cones sputtered at normal incidence, with heights ranging from 80 to 230 nm as determined by e.g. AFM and SEM.