Silicon Germanium Alloys For Photovoltaic Applications

Silicon-Germanium Alloys for Photovoltaic Applications provides a comprehensive look at the use of Silicon-Germanium alloys Si1-xGex in photovoltaics. Different methods of Si1-xGex alloy deposition are reviewed, including their optical and material properties as function of Ge% are summarized, with SiGe use in photovoltaic applications analyzed. Fabrication and characterization of single junction Si1-xGex solar cells on Si using a-Si as emitter is discussed, with a focus on the effect of different Ge%. Further, the book highlights the use Si1-xGex as a template for lattice matched deposition of III-V layers on Si, along with its challenges and benefits, including financial aspects. Finally, fabrication and characterization of single junction GaAsxP1-x cells on Si via Si1-xGex is discussed, along with the simulation and modeling of graded SiGe layers and experimental model verification. Includes a summary of SiGe alloys material properties relevant for solar research, all compiled at one place Presents various simulation models and analysis of SiGe material properties on solar cell performance Includes a cost-analysis for III-V/Si solar cells via SiGe alloys

Despite the vast knowledge accumulated on silicon, germanium, and their alloys, these materials still demand research, eminently in view of the improvement of knowledge on silicon-germanium alloys and the potentialities of silicon as a substrate for high-efficiency solar cells and for compound semiconductors and the ongoing development of nanodevic

Today, the silicon feedstock for photovoltaic cells comes from processes which were originally developed for the microelectronic industry. It covers almost 90% of the photovoltaic market, with mass production volume at least one order of magnitude larger than those devoted to microelectronics. However, it is hard to imagine that this kind of feedstock (extremely pure but heavily penalized by its high energy cost) could remain the only source of silicon for a photovoltaic market which is in continuous expansion, and which has a cumulative growth rate in excess of 30% in the last few years. Even though reports suggest that the silicon share will slowly decrease in the next twenty years, finding a way to manufacture a specific solar grade feedstock in large quantities, at a low cost while maintaining the quality needed, still remains a crucial issue. Thin film and quantum confinement-based silicon cells might be a complementary solution. Advanced Silicon Materials for Photovoltaic Applications has been designed to describe the full potentialities of silicon as a multipurpose material and covers: Physical, chemical and structural properties of silicon Production routes including the promise of low cost feedstock for PV applications Defect engineering and the role of impurities and defects Characterization techniques, and advanced analytical techniques for metallic and non-metallic impurities Thin film silicon and thin film solar cells Innovative quantum effects, and 3rd generation solar cells With contributions from internationally recognized authorities, this book gives a comprehensive analysis of the state-of-the-art of process technologies and material properties, essential for anyone interested in the application and development of photovoltaics.

Three sets of experiments were conducted using femtosecond transient absorption methods.