Silicon is an abundant element and is produced in large quantities for the electronic industry. The falling price of this commodity also feeds the growth of solar photovoltaics (PV). However, solar cells (SCs) based on bulk semiconductors have quite limited maximum attainable performance. Therefore, new principles and materials are being investigated to build the third generation of SCs with improved conversion efficiency achieved by the optimized harvesting of the solar spectrum, improved carrier generation, better light management, etc. The unique properties of semiconductor nanostructures (tuning of optoelectronic properties by the quantum confinement effect, stronger interaction with light, etc.) can be exploited to fabricate novel types of high-efficiency solar cells. Here, again, silicon along with carbon and germanium (group IV elements) is about to play a major role.
In view of the increasing research effort devoted to nanostructures’ applications in PV, this book aims to provide a background to students and newcomer researchers as well as to point out some open questions and promising directions for future development. It presents a useful overview of group IV nanostructures for PV, which includes the theoretical background, presentation of main solar cell principles, technological aspects, and nanostructure characterization techniques, and finishes with the design and testing of prototype devices. It is not intended to be just a review of the most up-to-date literature, but the authors aim to provide an educative background of the field. All authors are renowned researchers and experienced teachers in the field of semiconductor nanostructures and photovoltaics.
Table of Contents
Introduction to photovoltaics and potential applications of group IV nanostructures; J. Valenta, S. Mirabella
Dielectric function and spectrophotometry: from bulk to nanostructures; C. Summonte
Ab initio calculations of the electronic and optical properties of group IV semiconductor nanostructures embedded in different matrices; R. Guerra, S. Ossicini
Silicon nanoclusters embedded in dielectric matrices: nucleation, growth, crystallization, defects; D. Hiller
Excited-state relaxation in group IV nanocrystals investigated using optical methods; F. Trojánek, P. Malý, I. Pelant
Carrier multiplication in isolated and interacting silicon nanocrystals; I. Marri, M. Govoni, S. Ossicini
The introduction of majority carriers into group IV nanocrystals; D. König
Electrical transport in Si-based nanostructured superlattices; B. Garrido, S. Hernándes, Y. Berencén, J. López-Vidrier, J. M. Ramírez, O. Blázquez, B. Mundet
Ge nanostructures for harvesting and detection of light; A. Terrasi, S. Cosentino, I. Crupi, S. Mirabella
Application of surface-engineered silicon nanocrystals with quantum confinement and carbon nanomaterials in solar cells; V. Svrcek, D. Mariotti
Prototype PV cells with Si nanoclusters; S. Janz, P. Löper, M. Schnabel
Jan Valenta is professor of quantum optics and optoelectronics at the Department of Chemical Physics and Optics, Charles University, Prague. His research is oriented toward optical properties of semiconductor nanostructures, especially silicon. He is developing special spectroscopy set-ups and methods to measure photo- and electroluminescence spectra (down to single nano-objects), optical gain, and absolute quantum yields. His other interests include the history of science, scientific photography, and science-for-art applications. He is co-author (with I. Pelant) of the textbook Luminescence Spectroscopy of Semiconductors (Oxford, 2012).
Salvo Mirabella received his laurea (1999) and PhD (2003) in physics from the University of Catania, Italy, and is now researcher at the Institute for Microelectronics and Microsystems, National Council of Research (CNR IMM), Italy. His research activity is mainly experimental, focusing on group IV advanced materials for applications in photovoltaics (light absorption mechanisms in Si- or Ge-based nanostructures, sunlight-energy conversion, and transparent conductive electrodes) and microelectronics (point-defect engineering and dopant diffusion in crystalline or amorphous semiconductors and ion beam modification of materials).
"It is commonly accepted that nanostructures, whose properties can be conveniently tuned by size adjustments, will provide the materials basis for the next generation of highly efficient solar energy solution. That is in particular true for photovoltaics, possibly the most elegant solar energy harvesting strategy. There are many reasons why the first-generation PV is dominated by silicon; most of them will apply also to the next-generation solutions and that defined importance of nano-Si for the future photovoltaics. This book provides an excellent introduction to the field and a comprehensive overview of the state of the art in this vividly developing discipline, with experimental as well as theoretical advancements being presented in parallel."
—Prof. Tom Gregorkiewicz, University of Amsterdam, the Netherlands