Karl Leo Libri

Focusing on Bloch oscillations, this book provides a comprehensive overview of a rapidly evolving field, addressing its diverse aspects for the first time. It introduces essential concepts and explores the physics of high field transport through various experimental techniques, including optical spectroscopy and transport experiments. Additionally, the text discusses potential applications and future trends, making it a valuable resource for understanding current advancements and directions in this area of study.

This volume presents the results of a multi-year research programme funded by the Deutsche Forschungsgemeinschaft (German Research Council), which explains how organic solar cells work. In this new promising photovoltaic technology, carbon-based materials are deposited by low-cost methods onto flexible substrates, thus allowing devices which open completely new applications like transparent coatings for building, solar cells integrated into clothing or packages, and many more. The investigation of organic solar cells is an interdisciplinary topic, covering physics, chemistry and engineering. The different chapters address topics ranging from the synthesis of new organic materials, to the characterization of the elementary processes such as exciton transport and separation, and the principles of highly efficient device design.

The purpose of this book is to review the current state of this quickly developing field. Up until now, there has been no concise review available of the rather diverse aspects of this field. This book gives a basic introduction to the concepts behind Bloch oscillations. It describes how the physics of high field transport has been investigated through a broad range of experimental techniques such as interband and intraband optical spectroscopy and transport experiments. Possible applications and further trends are also discussed.

This thesis reports about the dynamics of coherent optical excitations in semiconductors. The emphasis is put on the initial coherent regime in the first few picoseconds after excitation. The experiments were performed with time-resolved non-linear optical techniques on GAAs/AlGaAs heterostructures.