Fabrication Idea Two-Dimensional Photonic Crystals by Growing Freshwater Pearls Induced by Rare Earth Cerium

Recently, biological system has revealed astonishing complex photonic structures. Freshwater pearls shows striking optical effects, such as reflection and interference, which closely related to its nanometer-scale multiplayer structure. In this paper, we tried to fabricate idea biological two-dimensional (2D) photonic crystals by growing freshwater pearls induced by Rare Earth Elements (REE) Cerium at a concentration of 1.2 mg•L-1. Comparing with the reference pearls cultured in nature freshwater, the superficial microstructure of REE pearls and their glossiness have taken large changes. The nacre of the REE pearls is structured 2D periodic photonic crystals layered structure, and each layer is composed by regular aragonite sheets, while the nature pearls has a mesa structure made of the spindly blocks, which were investigated by means of scanning electron microscopy (SEM). The glossiness of the pearls corresponds with the microstructure, the REE pearls possessing idea photonic crystals have higher glossiness than that of the nature pearls, which attribute to the strong interference effect of light on the photonic structure of REE pearls. It also provides an opportunity to grow perfect photonic crystals by culturing water pearls.