With the non-renewable sources of nature diminishing and the global warming effect increasing, Solar energy is vital in the present times considering the fact that the power demand in the world is a never ending process. And the emergence of the solar cells in the 19th century has signified the importance of solar energy today, in our lives.
A solar cell is a device converting the sunlight energy directly into electricity with the use of the photovoltaic effect. The term “photovoltaic” is used since 1849, derived from Greek ‘phos’ meaning “light” and ‘voltaic’ meaning “electric” from the name of the Italian physicist Volta. These solar cells or the photovoltaic cells today are used to make solar panels, solar modules, or photovoltaic arrays.
The photovoltaic effect was recognized first by the French physicist A. E. Becquerel in 1839, but it was in 1883 that the first solar cell (selenium-based) was actually built by Charles Fritts. Later Aleksandr Stoletov, the Russian physicist, built the first solar cell based on the outer photoelectric effect. It was Albert Einstein who actually explained the photoelectric effect in 1905 for which he was awarded Nobel Peace Physics Prize in 1921.
It was only in 1954 that the solar power technology fully arrived, in Bell Laboratories, where Daryl Chapin with his colleagues invented the first practical device for converting sunlight into electrical power, when they were experimenting with semiconductors and accidentally realized that silicon doped with certain impurities was actually very sensitive to light. This finally resulted in the production of the first useful solar cell with the efficiency for sunlight energy conversion of about 6%. Thus the process of reproduction and evolution with a chain culminating into different types of solar cells continue till today.
Though selenium gave way to silicon which dominated the solar cell production in the 20th century and still does, however, today we have several other types of solar cells gaining momentum like cadmium telluride, amorphous silicon and CIGS, among others. These semiconductors have become very famous of late to create several different kinds of solar cell like plastic or polymer, dye-sensitized, organic or the monocrystalline silicon, copper-indium selenide, nanocrystalline solar cells and others.
The challenge of the increasing photovoltaic efficiency is of great interest as much of the solar industry is focused on the most cost efficient technologies in terms of the cost per generated power. This with the recent breakthroughs in the field of solar energy has made the use of solar cells more competitive these days. For instance, in a recent research, scientists have verified experimentally that the hot electrons could double the solar cell power efficiency without cooling it down; or the Nanotechnology that uses nanomaterial composites for enhancing the overall solar cell efficiency is another major step in this field.
This source of power for all communications and scientific satellites is expanding rapidly with more scope in future and is fast becoming a key element of the renewable energy effort to reduce the use of fossil fuels to combat the already emerging global warming. Since the global electricity requirements are expected to double in the next 40 years, more and more cars will also be fuelled by electric power, apart from the use of solar cells in homes, businesses or other applications. This has also highlighted the importance of the Laser technology that can contribute to optimizing the manufacturing costs and efficiency of solar cells. With technological advancements and expanding applications, the solar cell costs are expected to fall in future making an easy-buy for average customers as well.