The book "Thin-Film Solar Cells" offers a comprehensive analysis of the development and application of thin-film solar cells as a promising technology in the field of renewable energy. Given the global challenges posed by fossil fuels and their environmental impacts, the need to explore and implement clean energy sources is becoming increasingly urgent. This technical book highlights the advancements in photovoltaic technology, particularly the reduction in solar cell costs achieved over the past two decades through intensive research and development efforts. It discusses how thin-film solar cells can play a key role in future energy supply by providing a cost-effective and environmentally friendly alternative to conventional energy sources. The content is of interest to both professionals and students who wish to engage with the latest developments in solar energy.