Status and perspectives of crystalline silicon photovoltaics in research and industry

Crystalline silicon solar cells are today's main photovoltaic technology, enabling the production of electricity with minimal carbon emissions and at an unprecedented low cost. This Review discusses the recent evolution of this technology, the present status of research and industrial development, and the near-future perspectives. Crystalline silicon (c-Si) photovoltaics has long been considered energy intensive and costly. Over the past decades, spectacular improvements along the manufacturing chain have made c-Si a low-cost source of electricity that can no longer be ignored. Over 125 GW of c-Si modules have been installed in 2020, 95% of the overall photovoltaic (PV) market, and over 700 GW has been cumulatively installed. There are some strong indications that c-Si photovoltaics could become the most important world electricity source by 2040-2050. In this Review, we survey the key changes related to materials and industrial processing of silicon PV components. At the wafer level, a strong reduction in polysilicon cost and the general implementation of diamond wire sawing has reduced the cost of monocrystalline wafers. In parallel, the concentration of impurities and electronic defects in the various types of wafers has been reduced, allowing for high efficiency in industrial devices. Improved cleanliness in production lines, increased tool automation and improved production technology and cell architectures all helped to increase the efficiency of mainstream modules. Efficiency gains at the cell level were accompanied by an increase in wafer size and by the introduction of advanced assembly techniques. These improvements have allowed a reduction of cell-to-module efficiency losses and will accelerate the yearly efficiency gain of mainstream modules. To conclude, we discuss what it will take for other PV technologies to compete with silicon on the mass market.

Automated summary

This paper reviews the recent evolution of crystalline silicon solar cells, analyzes the current status of research and industrial development, and looks into the future prospects. The improvements in materials and processing have greatly reduced the cost and increased the efficiency of crystalline silicon photovoltaics, making it an important low-cost source of electricity. The paper also discusses the challenges and requirements for other photovoltaic technologies to compete with silicon on the mass market.