Ion Exchange, Self-Assembly, and Light Emission. A Dance of Ions and Light
This thesis explores ion exchange, self-assembly, and light emission for functional optical materials. Nature-inspired self-assembly has the power to assemble composite materials such that functionality emerges from the hierarchical order within. Inherently, the synthesis of a material determines its final composition. In this thesis we explore how metal salts, carbonate, and silicate form hierarchical metal carbonate/silica architectures. These architectures enable light manipulation, but other functionalities such as emitting light would require a different material composition that cannot be accessed via the same synthesis route. Conventionally, materials have been regarded as permanently defined by their constituting elements. Here, ion exchange reactions bring an opportunity to change material compositions post-synthesis. We harness the potential of the assembly process to form metal carbonate microarchitectures and, through ion exchange reactions, change the material composition to create a light-emitting perovskite. The possibility to change material composition is taken one step further through performing ion exchange reactions selectively on some areas of the material. Instead of positioning multiple materials next to each other, we can program the conversion of one material into different materials locally.
Collectively, these approaches may lead to integrated devices fully designed through self-assembly and ion exchange. Essentially, optoelectronics is a case study; the same concept holds potential for many fields, for example, catalysis and batteries. Ultimately, the increasing control over artificial self-assembly processes, combined with the versatility of ion exchange routes, will enable us to fabricate architectures and materials that are inaccessible with current fabrication techniques.