Energy harvesting devices photovoltaic

Despite some remarkable recent successes, it is clear that the examples discussed in this chapter represent only the tip of the iceberg. More research in this relatively new area is needed to fully explore the possibilities offered by these materials, for example, in the production of active as well as passive devices. This underlines more than ever the great need for creative synthetic chemistry, which will ensure that fullerenes may eventually become an important building block of future technologies, such as optoelectronics, batteries, photovoltaics and, in a more general sense, as a new and realistic class of energy harvesting materials. 

Siores et al. (2010) have developed a fibre stmcture that can be used to convert mechanical and light energy into electrical energy. The hybrid energy conversion device consists of a piezoelectric polymeric structure coated with a photovoltaic system. The fibre is claimed to be flexible enough to be converted into textiles for energy harvesting. 

A similar approach was achieved by other groups (Kumar and Kim, 2012) in reporting hybrid devices of photovoltaic and piezoelectric that improve the transportation of electrons and energy harvesting. Controlled ZnO nanostructures in various complex nanoarchitectures improve charge collection. Solar and mechanical energies are utilized in this case because they can work in the absence of either solar or mechanical energy. 

CNTs, graphene and their compounds possess exceptional electrical properties for organic materials, and they have a huge potential in electrical and electronic applications, such as photovoltaics, sensors, semiconductor devices, display devices, conductors, smart textiles, and energy conversion devices (e.g., fuel cells, harvesters, and batteries). CNTs and graphene can greatly contribute to sustainable energy supplies and they are widely used in biomedicine. 

Ideally, all photons with a wavelength of about 900 nm or shorter should be harvested and converted to electric current. This limit is derived from thermodynamic considerations showing that the conversion efficiency of any single-junction photovoltaic solar converter peaks at approximately 33% near the threshold energy of lAeV.1 2 There are numerous ways to convert the solar radiation directly into electrical power or chemical fuel. The silicon solar cell is the most efficient in this respect. Nevertheless, the capital cost of such devices is not attractive for large-scale applications. 

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