When structure–property relationships
are discussed in inorganic
chemistry and materials science, the common perception is that materials
with the same composition and atomic arrangement have the same properties.
In this laboratory experiment, we show that processingthe exact conditions under which materials are madecan
in fact significantly alter the properties of materials. Using halide
perovskite as a model, we demonstrate that the same set of starting
chemicals, when processed differently, can form distinct material
platforms–single crystals, thin films, and nanoparticles, the
last of these being made of crystallites that are 10,000 times smaller
than the first. We then show how this difference in crystal size leads
to major changes in the optical properties of the materials, despite
the fact that they have the same composition and crystal structure.
The experiment provides an example of how the basic concept of crystallization
leads to different materials and how processing affects the crystal
size and thus influences the structure–property relationship.