Materials
Various materials display varying efficiencies and have varying costs. Materials for efficient solar cells must have characteristics matched to the spectrum of available light. Some cells are designed to efficiently convert wavelengths of solar light that reach the Earth surface. However, some solar cells are optimized for light absorption beyond Earth's atmosphere as well. Light absorbing materials can often be used in multiple physical configurations to take advantage of different light absorption and charge separation mechanisms.
Materials presently used for photovoltaic solar cells include monocrystalline silicon, polycrystalline silicon, amorphous silicon, cadmium telluride, and copper indium selenide/sulfide.
Many currently available solar cells are made from bulk materials that are cut into wafers between 180 to 240 micrometers thick that are then processed like other semiconductors.
Other materials are made as thin-films layers, organic dyes, and organic polymers that are deposited on supporting substrates. A third group are made from nanocrystals and used as quantum dots (electron-confined nanoparticles). Silicon remains the only material that is well-researched in both bulk and thin-film forms.
Read more about this topic: Solar Cell
Famous quotes containing the word materials:
“Herein is the explanation of the analogies, which exist in all the arts. They are the re-appearance of one mind, working in many materials to many temporary ends. Raphael paints wisdom, Handel sings it, Phidias carves it, Shakspeare writes it, Wren builds it, Columbus sails it, Luther preaches it, Washington arms it, Watt mechanizes it. Painting was called “silent poetry,” and poetry “speaking painting.” The laws of each art are convertible into the laws of every other.”
—Ralph Waldo Emerson (1803–1882)
“Realism to be effective must be a matter of selection. ... genius chooses its materials with a view to their beauty and effectiveness; mere talent copies what it thinks is nature, only to find it has been deceived by the external grossness of things.”
—Julia Marlowe (1866–1950)
“If our entertainment culture seems debased and unsatisfying, the hope is that our children will create something of greater worth. But it is as if we expect them to create out of nothing, like God, for the encouragement of creativity is in the popular mind, opposed to instruction. There is little sense that creativity must grow out of tradition, even when it is critical of that tradition, and children are scarcely being given the materials on which their creativity could work”
—C. John Sommerville (20th century)