Microstructure Control in Transparent Conductive Oxides and Metal Halide Perovskites for Solar Cells

We are living in a time when the demand for energy continues to rise from day to day. The increase is driven by population growth, industrial expansion and increased use of artificial intelligence. Meeting those demands while adhering to international climate goals such as those outlined in the Paris Agreement, requires a rapid transition toward low-carbon and renewable energy technologies. Among all renewable sources, solar energy is by far the most abundant, and photovoltaics (PV) have emerged as one of the most impactful technologies. The global installation of PV capacity continues to grow exponentially, demonstrating both its maturity and its central role in our clean-energy future. As silicon PV approaches its practical efficiency limits, emerging materials, such as metal halide perovskites (MHPs), offer a pathway forward, particularly through tandem configurations that can outperform single-junction silicon cells and open the door to new device architectures. A central thread running throughout this thesis is the influence of microstructure on the functional performance of materials used in perovskite (PVK) and perovskite/silicon (PVK/Si) tandem solar cells. Following a general introduction to the motivation behind this work, photovoltaic technologies, and a focused overview of transparent conductive oxides (TCOs) and MHPs in Chapter 1, as well as vapor-phase deposition methods, pulsed laser deposition (PLD), and characterization techniques in Chapter 2, the subsequent chapters systematically build on this theme. Each chapter examines how controlling microstructure can address key material-level challenges in next-generation PV devices.