Hybrid structures and optical effects in Morpho scales with thin and thick coatings using an atomic layer deposition method

Thin and thick Al2O3 coatings are deposited onto the surfaces of the cover and ground scales in the butterfly Morpho menelaus by low-temperature atomic layer deposition method. By spectral measurements and electronic microscopy, it is revealed that the morphologies of the hybrid structures encapsulated with thin coatings and thick coatings behave in a different way and thus the distinguishing color changes in both cover and ground scales. Theoretical analyses show that the coloration change can be attributed to the correlations of the naturally occurring photonic structures and the coating thicknesses. The different structural origins of the coloration in cover scales and ground scales lead to different optical performances as the coating increases its thicknesses in succession. The study presented offers an alternating route to produce desirable nanostructures such as nanolines and artificial photonic devices such as solar absorbers, and also the intact biotemplates an indirect analysis of structural characterizations and their optical effects.