This textbook bridges the gap between basic literature on the physics of solar cells and highly specialized books about photovoltaic solar energy conversion. It is intended to give students with a background in engineering, materials science, chemistry or physics a comprehensive introduction to materials concepts for solar cells. To this end, general principles of solar cells and materials demands are explained in the first part of this book. The second part is devoted to the four classes of materials concepts for solar cells: solar cells based on crystals of silicon, epitaxial layer systems of III-V semiconductors, thin-film absorbers on foreign substrates, and nano-composite absorbers.