Jonathan Scragg documents his work on a very promising material suitable for use in solar cells. Copper Zinc Tin Sulfide (CZTS) is a low cost, earth-abundant material suitable for large scale deployment in photovoltaics. Jonathan pioneered and optimized a low cost route to this material involving electroplating of the three metals concerned, followed by rapid thermal processing (RTP) in sulfur vapour. His beautifully detailed RTP studies combined with techniques such as XRD, EDX and Raman reveal the complex relationships between composition, processing and photovoltaic performance. This exceptional thesis contributes to the development of clean, sustainable and alternative sources of energy