Reflective structural colour is an hot-topic in research
nowadays as a substitute for dyes and pigments. The ideal system should
provide high reflectance efficiency and chromaticity, along with good
tunability to obtain the required colour. In this study, we demonstrate the
production of high reflectance efficiency and good chromaticity structural
colours based on the Fabry–Pérot effect using cellulose nanofibers (CNF) as
the cavity layer. Using spin-coating to fabricate the cavity layer, this
device presents a layer-by-layer fabrication approach with high
reproducibility to obtain highly reflective cavities using simple fabrication
methods and easily scalable. The fabrication process also presents high
tunability by altering spin-coat conditions. The use of a broadband absorbent
layer on top of the cavity leads to high chromaticity, with well defined
reflectance peaks.