Células fotovoltaicas de silício cristalino: tecnologias e processos de fabricação.

Abstract

The production of solar cells has grown gradually in past decades in response to demands for renewable and cleaner energy generation. The expansion in the photovoltaic market results in expansion in the silicon market, since the manufacture of electronic and photovoltaic devices is the activity that demands the most silicon throughout the world. The production chain of PV industry includes various stages of production, from extraction and production of metallurgical silicon to the purification and refining for applications in semiconductors and solar cells. Hence, throughout the work is presented the technological processes of manufacture of crystalline silicon based solar cells, since these are the technology with the largest representation, about 81%, in the market. In the work is presented the various aspects of photovoltaic generation, the main parameters of solar radiation are discussed, the operation principal of cells, as well as the efficiency of these devices. With respect to silicon, it is shown the different ways of obtaining solar grade silicon, raw material for solar cell production, the different steps of the process of growing monocrystalline and polycrystalline silicon ingots, as the Czochralski method and the Fusion Zone method, are discussed. It is noticed that the large majority of the methods being applied and developed aim to ensure the highest possible efficiency is reached ensuring also the competitiveness and attractiveness of the photovoltaic market.