Photovoltaic And Photoelectrochemical Solar Energy Conversion

In recent years there has been an increasing interest in syscems which enable the conversion of solar energy into electri calor chemical energy. Many types of systems have been proposed and studied experimenta11y, the fundamentals of which extend from solid state physics to photo- and electrochemistry. For most of the systems considered excitation of an electron by absorption of a photon is fo1lowed by charge separation at an interface. It follows that the different fields involved (photovo1taics, photo electrochemistry, photogalvanics, etc.) have several essential aspects in common. It was the main purpose with the NATO Advanced Study Insti tute held at Gent, Belgium, from August 25 to September 5, 1980, to bring together research workers specializing in one of these fields in order to enab1e them not only to extend their knowledge into their own field but also to promote the interdisciplinary exchange of ideas. The scope of the A.S.I. has been 1imited to systems which have not or have hardly reached the stage of prac tica1 development. As a consequence, no lectures on economica1 aspects of solar energy conversion have been included. The topics covered in this volume are the fundamentals of recombination in solar ce1ls (P. Landsberg), theoretical and experimental aspects of heterojunctions and semiconductor/metal Schottky barriers (J.J. Loferski, W.H. Bloss and W.G. Townsend), photoelectrochemica1 ce11s (H. Gerischer and A.J. Nozik), pho- v PREFACE vi ga1vanic ce11s (W.J. Albery) and fina11y, surfactant assemb1ies (M. Grätzel).

This book explains the conversion of solar energy to chemical energy and its storage. It covers the basic background; interface modeling at the reacting surface; energy conversion with chemical, electrochemical and photoelectrochemical approaches and energy conversion using applied photosynthesis. The important concepts for converting solar to chemical energy are based on an understanding of the reactions’ equilibrium and non-equilibrium conditions. Since the energy conversion is essentially the transfer of free energy, the process are explained in the context of thermodynamics.

Photochemical Conversion and Storage of Solar Energy contains the proceedings of the Third International Conference on Photochemical Conversion and Storage of Solar Energy held in Boulder, Colorado, on August 3-8, 1980. The papers review the state of the art in the areas of photochemistry and photoelectrochemistry in the context of solar energy conversion and storage. Topics covered include photosynthetic quantum conversion; biomimetic systems for solar energy conversion; and photochemical electron transfer reactions in homogeneous solutions. This volume is comprised of 11 chapters and begins by describing an artificial photosynthetic system that can capture solar quanta and convert them into a stable chemical form. The discussion then turns to biomimetic approaches to solar energy conversion; fluorescent concentrators for photovoltaic cells; requirements for homogeneous photoredox chemistry in inorganic systems; and the use of inorganic components coupled with catalysts in heterogeneous assemblies for photochemical water splitting. The following chapters focus on photogalvanic cells, electrochemical photovoltaic cells, and photoelectrosynthetic reactions at the semiconductor-electrolyte interface. The final chapter examines the thermodynamic limits on photoconversion and storage of solar energy. This monograph will be of interest to chemists and other scientists concerned with the photochemical aspects of solar energy conversion and storage.

In this book, expert authors describe advanced solar photon conversion approaches that promise highly efficient photovoltaic and photoelectrochemical cells with sophisticated architectures on the one hand, and plastic photovoltaic coatings that are inexpensive enough to be disposable on the other. Their leitmotifs include light-induced exciton generation, junction architectures that lead to efficient exciton dissociation, and charge collection by percolation through mesoscale phases. Photocatalysis is closely related to photoelectrochemistry, and the fundamentals of both disciplines are covered in this volume.

Solar Energy Conversion and Storage: Photochemical Modes showcases the latest advances in solar cell technology while offering valuable insight into the future of solar energy conversion and storage. Focusing on photochemical methods of converting and/or storing light energy in the form of electrical or chemical energy, the book: Describes various types of solar cells, including photovoltaic cells, photogalvanic cells, photoelectrochemical cells, and dye-sensitized solar cells Covers the photogeneration of hydrogen, photoreduction of carbon dioxide, and artificial/mimicking photosynthesis Discusses the generation of electricity from solar cells, as well as methods for storing solar energy in the form of chemical energy Highlights existing photochemical methods of solar energy conversion and storage Explores emerging trends such as the use of nanoparticles Solar Energy Conversion and Storage: Photochemical Modes provides a comprehensive, state-of-the-art reference for graduate students, researchers, and engineers alike.

In the past 12-15 years an essentially new trend in electrochemistry has sprung up around the problem of solar energy conversion. Strictly speaking, this is not a purely electrochemical but an interdisciplinary field involving the fields of cataly sis, corrosion, chemistry of disperse systems, and others. Nevertheless, electro chemistry, to be more exact, photoelectrochemistry of semiconductors, provides a theoretical basis for new methods of converting light energy into electrical or chemical energy, which, we hope, shall find practical application in the not so dis tant future. In the past years, this field has been discussed amply and at length in special monographs (e. g. , in Ref. [l]). Therefore, in this book the photoelectro chemistry of semiconductors is presented in a concise form (exceptions are only specific problems which have been elucidated incorrectly or have not been covered completely in the literature). In this compact monograph we have aban doned the principle of "self-seclusion": for a more deep insight into the funda mentals of electrochemistry, photoelectrochemistry, and physics of semiconduc tors the reader shall have to refer to the below-cited manuals, while information on the physicochemical properties of particular semiconductor electrodes can be taken, e. g. , from Refs. [2, 3].