It has been said that only God can make a tree. However, man is attempting to achieve the humbler ambition of making a leaf - a supramolecular or microstructured assembly that can produce a fuel or electric power in a reaction driven by sunlight. Water splitting, carbon dioxide fixation and electrical power production are all possible in appropriately designed photochemical or photoelectrochemical devices. Elegant in conception but often complex and short-lived, these are the least-developed of the photoconversion technologies described in this series of books. It is nonetheless possible that they have the greatest long term potential. There is a good coherence to the book's structure despite the contributions from multiple authors. The coherence is assisted by an excellent introductory chapter by Archer, as well as consistency in formatting and figure style throughout the book.