Sb2Te3 exhibits a plethora of fundamentally relevant electronic phenomena enabling electronic phase change memory cells, thermoelectric devices, and three-dimensional topological insulator structures. Thus, the controlled growth of nanostructures and thin films with well-defined electronic properties is of utmost importance. Previously, our group observed symmetric infrared domains in hexagonal Sb2Te3 nanoplatelets from a solvothermal chemical synthesis. The relative optical contrast observed was indirectly linked to the formation of regions with different defect densities (charge carrier concentrations). This raises two major questions, which we answer in this study: Is the domain formation restricted to the specific platelet growth process? No! Do the infrared spectra of both domains really follow a “Drude-like” free charge carrier response? Yes! By controlling the initial water concentration, we promote the …