Photoluminescence properties of zinc white

Zinc white pigment has characterized artist’s palettes from the end of the eighteenth century up the twentieth century. It thus belongs to the modern pigments which were industrially produced by inorganic material (ZnO). This new category of pictorial materials interested conservators and scientists mainly for its behavour with aging. For this reason, this work focuses on the understanding of photo-physical behaviour of zinc white based on a time-resolved analysis of photoluminescence emission of historical samples. This study allowed the characterization of the decay kinetic properties of photoluminescence emissions. All historical samples showed near-band-edge and trap state emissions, typically occurring in semiconductors, that were modified by the interaction of the pigment with the surrounding organic binding material. The study further suggests that zinc carboxylates, detected in all historical samples, could be responsible for changes in emission mechanisms. Generally, data demonstrates how time-resolved photoluminescence spectroscopy is a powerful method for elucidating the nature of the mechanism processes in luminescent semiconductor pigments.