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With growth in 2009 suffering from recession and an ongoing credit crunch, this paper presents a review of the key trends in cell and module manufacture for the crystalline silicon (c-Si) PV module market. The c-Si segment remains the largest segment, and is competing effectively with less mature thin-film technologies. PV is still a largely uneconomic way to generate power, and requires subsidy to maintain sales volume and growth. While subsidies exist, the industry treads the narrow path of growing at a healthy clip, developing robust technology and business models, and mapping paths to profitable business without subsidies once PV installations become economically viable.

Heat transfer and control of the temperature field are important in the production of silicon solar cell wafers. Present work focuses on the first steps of the production chain, i.e. crystallization and wafering. For the crystallization process, control of heat transfer is crucial for the ingot quality in terms of grain structure, impurity distribution, particle formation, and ingot stresses. Heat transfer is also important during subsequent processes, in particular the wire sawing of the silicon blocks into wafers. The paper emphasises the role of heat transfer and explains the consequences for these processes. Examples from experimental trials and measurements are combined with models and simulation methods.

An improved understanding of multicrystalline wafer quality can explain variations in cell performance across multicrystalline silicon blocks. Infrared scanning can detect precipitates in a silicon block, while photoluminescence combined with defect etching can reveal needle-like precipitates along the grain boundaries. Such precipitates typically lead to reduced shunt resistance. Crystallographic defects that lower the current collection and the final cell efficiency can also be identified. Understanding the influence of these defects is important for the development of a crystallization technology that results in a substantially better cell efficiency. The use of the improved material quality in an innovative cell and module technology have led to the world record module efficiency of 17%. This paper will illustrate one example of how an improved understanding of multicrystalline wafer quality can explain the variations in cell performance.

Multi-wire sawing is currently the most efficient slicing technology for silicon wafers in the photovoltaic industry. Nevertheless, the wafer producers are faced with major cost reductions in the production process and the demand for high-quality, very thin wafers with a total thickness variation less than 10% of the average wafer thickness. One approach to this is the understanding of the role of slurry, specifically the abrasives used in the multi-wire sawing process. In the past few years, more and more scientific investigations have been conducted and are summarised in this article.

Although simple in concept, a photovoltaic solar cell is a difficult feat of technology in execution. The challenge of balancing cell structure design, material optimization and module technology to achieve efficient, low-cost modules that perform in aggressive environments for up to a generation is huge. The modules’ structure has to support and protect a thin, fragile slice of semiconductor, while ensuring a stable environment free from contamination and moisture with little or no change in the incident light on the cell.

In the perpetual struggle to reduce the costs associated with PV energy generation, one aspect of the manufacturing process has potential to shine. To date, the PV sector is dominated by crystalline silicon wafers (90%), which largely use silver as the conducting medium for the front side grid, and to a lesser extent the backside contact. The conducting media are crucial to the overall efficiency of the cell by providing the means for current to flow when sunlight strikes the doped silicon wafer.

A new wafer technology, named CDS (Crystallization on Dipped Substrate), is under development and has been found to be effective in the reduction of wafer cost and silicon feedstock. CDS technology was applied to 156mm × 156mm sized wafers, obtained via the throughput of 1825cm²/min, and the resulting cell efficiency of 14.8% was confirmed.

Materials innovation in solar photovoltaic manufacturing has long played a key role in efforts to raise cell and module conversion efficiencies, improve overall device performance and reliability, and lower the overall cost per manufactured watt. Research and development in areas such as ultrathin-silicon wafering and replacement films for thin-film PV transparent conductive oxides often garner much of the industry’s attention.

Glass plays an increasingly important role in photovoltaics. The rising demand for solar modules is pushing the glass industry to the fore. As a result, mechanical engineering companies around the world are working to meet the demands of the solar industry, with the tremendous potential of glass, especially in the thin-film sector, at the epicentre of this effort.

Invented in their high efficiency version in the early 1990s, dye-sensitised solar cells (DSCs) entered the global market in 2007 with the first commercial modules based on this versatile, hybrid (organic-inorganic) technology. The 6-7% efficiency of the first modules is a result of their good performance in diffuse light conditions, allowing for the production of electricity both under cloudy conditions and indoors.