This work focuses on the optimization of the front side metallization process of industrial silicon solar cells. Since the state-of-the-art screen-printed contact has some well-known limitations, as a high contact resistance, a low lateral conductance and a low aspect ratio (height : width), alternative metallization technologies suitable for a one-layer grid structure of solar cells were reviewed. These include stencil-printing, pad-printing, ink-jet printing and dispensing. However, none of these technologies fulfills all the demands of a high-efficiency contact. Thus in this work the development of new concepts for the front side metallization was based on the two-layer contact structure. This structure has the advantage that every layer can be optimized individually. The requirement for the first layer is a small contact width, a low contact resistance, a sufficient adhesion to the underlying silicon surface as well as a good adhesion to the metal of the second layer. The task of the second layer is to collect the current from the first one, so its critical parameter is high line conductivity. Due to its major importance in the state-of-the-art industrial production, screen-printing was investigated as a reference process. The front side screen-printing process could be optimized by using hotmelt silver paste. Despite the different composition of the hotmelt compared to conventional paste, the rheology and hence the printability of the paste behaves similarly at elevated temperatures. The advantage of screen-printing hotmelt paste is the achievement of relatively high finger aspect ratios (1:3-1:4). Efficiencies of 18.0% on 12.5x12.5 cm2 Cz-silicon with an Al-BSF were obtained. Light-induced plating is used for the high-efficiency process in order to form the second layer of the proposed two-layer contact structure. Theoretical as well as experimental investigations allowed a profound understanding of the chemical reaction in the bath and optimum plating conditi.

Metallization is a key step in manufacturing of efficient and reliable solar cells. Written by world-wide renowned experts, this work covers metallization technologies, before describing ongoing R&D activities for the most relevant silicon solar cells metallization technologies. Later chapters deal with aspects of solar cell modules.

The world of today must face up to two contradictory energy problems: on the one hand, there is the sharply growing consumer demand in countries such as China and India. On the other hand, natural resources are dwindling. Moreover, many of those countries which still possess substantial gas and oil supplies are politically unstable. As a result, renewable natural energy sources have received great attention. Among these, solar-cell technology is one of the most promising candidates. However, there still remains the problem of the manufacturing costs of such cells. Many attempts have been made to reduce the production costs of “conventional” solar cells (manufactured from monocrystalline silicon using diffusion methods) by instead using cheaper grades of silicon, and simpler pn-junction fabrication. That is the ‘hero’ of this book; the heterojunction solar cell.

The most comprehensive, authoritative and widely cited reference on photovoltaic solar energy Fully revised and updated, the Handbook of Photovoltaic Science and Engineering, Second Edition incorporates the substantial technological advances and research developments in photovoltaics since its previous release. All topics relating to the photovoltaic (PV) industry are discussed with contributions by distinguished international experts in the field. Significant new coverage includes: three completely new chapters and six chapters with new authors device structures, processing, and manufacturing options for the three major thin film PV technologies high performance approaches for multijunction, concentrator, and space applications new types of organic polymer and dye-sensitized solar cells economic analysis of various policy options to stimulate PV growth including effect of public and private investment Detailed treatment covers: scientific basis of the photovoltaic effect and solar cell operation the production of solar silicon and of silicon-based solar cells and modules how choice of semiconductor materials and their production influence costs and performance making measurements on solar cells and modules and how to relate results under standardised test conditions to real outdoor performance photovoltaic system installation and operation of components such as inverters and batteries. architectural applications of building-integrated PV Each chapter is structured to be partially accessible to beginners while providing detailed information of the physics and technology for experts. Encompassing a review of past work and the fundamentals in solar electric science, this is a leading reference and invaluable resource for all practitioners, consultants, researchers and students in the PV industry.