Dye-sensitized solar cells: A new benchmark for electric power generation in Brazil

摘要

Since the first modern silicon solar cells have been launched in the early 50s by AT&T Bell Laboratories [1], research and development in Brazil still represents a small fraction of the current capacity to generate power due to the high import taxes associated to the solar-grade silicon. Brazil is one of the most favorable countries for solar energy implementation due to the large amount of solar irradiation received annually. In addition, it is one of the largest producers and exporters of metallurgic silicon worldwide. However, despite being a potential user and manufacturer of siliconbased PV modules, Brazil does not produce the solar-grade silicon in large-scale. As consequence, it makes the industrial production of the Brazilian solar cells a distant dream. In this sense, several other kinds of PV technologies have been suggested to overcome this situation. Dye-sensitized solar cell (DSSC), for example, is one of the most promising because of its low cost, easy fabrication, long-term stability and global efficiency comparable to silicon [2]. For Brazilian purposes, the majority of materials, that composes the DSSCs, are available in the national market, thus, decreasing theoverall module cost and stimulating the Brazilian economy. Currently, and contrary to the silicon market, Brazil has commercial production of DSSC technology, which drives even more the large-scale production of this new kind of solar cell. On the other hand, despite to be more suitable for Brazilian purposes nowadays, the global efficiency of DSSCs still remains lower than that attained with silicon-based PV modules. By this way, several studies were conducted so far in order to improve its light-to-electricity conversion where a wide range of changes have been suggested. Among them, we get modifications in the transporter semiconductor [3], dye molecules [4], electrolyte solution [5], counter-electrode [6], solid-liquid interface [7] and module design [8]. In this paper, a general dis- ussion about the main features of the dye-sensitized solar cells, as well as, its real situation for application on Brazilian scenario of sustainable energy is done. In addition, a discussion about modifications made so far, in order to equalize its global efficiency with those attained with silicon solar cells, is also conducted.