LAUSR

Functional capacities of lead halide perovskites are strongly dependent on their morphology, crystallographic texture, and internal ultrastructure on the nano‐ and the meso‐scale. In the last decade, significant efforts are directed towards the development of novel synthesis routes that would overcome the morphological constraints provided by the physical and crystallographic properties of these materials. In contrast, various living organisms, such as unicellular algae, have the ability to mold biogenic crystals into a vast variety of intricate nano‐architectured shapes while keeping their single crystalline nature. Here, using the cell wall of the dinoflagellate L. granifera as a model, sustainably harvested biogenic calcite is successfully transformed into nano‐structured perovskites. Three variants of lead halide perovskites CH3NH3PbX3 are generated with X = Cl−, Br− and I−; exhibiting emission peak‐wavelength ranging from blue, to green, to near‐infrared, respectively. The approach can be used for the mass production of nano‐architectured perovskites with desired morphological, textural and, consequently, physical properties exploiting the numerous templates provided by calcite forming unicellular organisms.