Materials
The majority of multi-junction cells that have been produced to date use three layers. These cells require the use of semiconductors that can be tuned to specific frequencies, which has led to most of them being made of gallium arsenide (GaAs) compounds, often germanium for the bottom-, GaAs for the middle-, and GaInP2 for the top-cell.
Read more about this topic: Multijunction Photovoltaic Cell
Famous quotes containing the word materials:
“Artists, whatever their medium, make selections from the abounding materials of life, and organize these selections into works that are under the control of the artist.... In relation to the inclusiveness and literally endless intricacy of life, art is arbitrary, symbolic and abstracted. That is its value and the source of its own kind of order and coherence.”
—Jane Jacobs (b. 1916)
“What is most interesting and valuable in it, however, is not the materials for the history of Pontiac, or Braddock, or the Northwest, which it furnishes; not the annals of the country, but the natural facts, or perennials, which are ever without date. When out of history the truth shall be extracted, it will have shed its dates like withered leaves.”
—Henry David Thoreau (1817–1862)
“Our job is now clear. All Americans must be prepared to make, on a 24 hour schedule, every war weapon possible and the war factory line will use men and materials which will bring, the war effort to every man, woman, and child in America. All one hundred thirty million of us will be needed to answer the sunrise stealth of the Sabbath Day Assassins.”
—Lyndon Baines Johnson (1908–1973)