Nanotechnology is an integral part of most of the research work carried out in today's world. It is also used in the research and development of solar panels to make them efficient. Basic technological information pertaining to solar panels without getting into the details about nanotechnology is presented in this article.Overview of High Efficiency Solar Panels
The multi-junction solar cells contain thin films manufactured by making use of the technology of molecular beam epitaxy. The metalorganic vapour phase epitaxy can also be used in the production these solar cells. Different semiconductors have their specific value of band gap energy. A semiconductors's band gap energy value allows it to absorb a certain light in an efficient way. That is why,0 the choice of an appropriate semiconductors matters a lot in the application of this technology. This is because maximum amount of energy has to be absorbed to make the solar cells efficient. The details, in brief, of the underlying technologies used for these solar panels (i.e. the 'Molecular beam epitaxy' and 'Metalorganic vapour phase epitaxy') is given below, in the hope that the information may prove useful to you.
Molecular Beam Epitaxy
It is one of the techniques used in depositing single crystals on to the substrate. This technique was developed in the 1960s in 'Bell Telephone Laboratories'. Alfred Y. Cho and J. R. Arthur were the ones who invented this technique. The single crystals are known for their unbroken edges. As the name suggests, 'epitaxy' is the technique used for manufacturing these solar cells. In the process of epitaxy, a monocrystalline substrate is used and monocrystalline film is deposited on it. A high vacuum environment is required for conducting the process of molecular beam epitaxy. The deposition rate of monocrystalline film in this method is very slow; it is less than 1000 nm per hour. The sublimation and condensation process of pure elements like arsenic and gallium is used to form wafers of these solar cells.
Metalorganic Vapour Phase Epitaxy
In the Metalorganic Vapour Phase Epitaxy, a chemical reaction is used. Use of chemical reaction in this method is opposed to the physical deposition technique (used in Molecular Beam Epitaxy) applied in 'Metalorganic Vapour Phase Epitaxy'. Chemical vapour deposition is the process used in Metalorganic Vapour Phase Epitaxy. The metal hydrides and metalorganic compounds which contain the necessary elements for manufacturing solar cells take part in a surface reaction. The pyrolysis process helps in the decomposition of these compounds and finally the pure elements are deposited on the substrate layer being used. Unlike the vacuum used for Molecular Beam Epitaxy, the gas medium is used during this process. The pressure that is maintained during this chemical process ranges from 2-100 kPa (Kilo Pascal).
Solar Panel Efficiency
The sunlight-to-electricity conversion efficiency is taken into account in determining whether a product is good enough to be used commercially. In the 1980s, conversion rate was around 16%' since then, the solar panel efficiency has gradually increased. Today, this number has gone up to 40%. Some of the companies in research and development of these modern solar panels claim to provide these equipments at an installation cost of $3 per watt. There are few companies in the market that offer solar panels with higher efficiency than the traditional ones. The solar panel efficiency comparison should be carried out so as to find the best product available in the market.