"Tandem collodial semiconductor devices for solar-driven water splitting applications" - Solar energy is the most prevalent form of renewable electricity on earth, though one major drawback is its intermittency over the course of the day. Semiconductor-liquid interfaces can be engineered to perform fuel-forming chemical reactions under illumination, like the evolution of hydrogen and oxygen from splitting water. In this case, solar energy is stored in chemical bonds that can be utilized on demand as a solar fuel. To be cost competitive with traditional fossil fuels, semiconductor-based solar fuel production requires materials that are efficient, stable, and earth-abundant. In this seminar, I will discuss efforts to develop colloidal semiconductor devices for solar-driven water splitting applications. First, I will outline strategies for coupling metal-oxide photoanodes to silicon-based photocathodes in a tandem configuration to produce sufficient photovoltage for splitting water. I will show that these strategies can be extended to the development of core-shell Si/metal oxide microwire arrays for water-splitting membranes. Finally, I will discuss efforts to structure these devices on multiple length scales in order to optimize each semiconductor independently. This work provides a materials-independent framework for the development of robust, inexpensive, and scalable tandem water-splitting materials.