Symposium C, 'Thin-Film Compound Semiconductor Photovoltaics' and Symposium FF, 'Compound Semiconductors for Generating, Emitting, and Manipulating Energy - II' were held on April 1-5 at the 2013 MRS Spring Meeting in San Francisco, California. This combined symposia Proceedings represents the latest technical advancements and information on compound semiconductors for generating, emitting, and manipulating energy from universities, national laboratories and industries. It provides insight into emerging trends in these exciting technologies.