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The Photovoltaic Effect
The photovoltaic effect is the basic physical process
through which a PV cell converts sunlight into electricity Sunlight
is composed of photons--packets of solar energy. These photons
contain different amounts of energy that correspond to the different
wavelengths of the solar spectrum. When photons strike a PV cell,
they may be reflected or absorbed, or they may pass right through.
The absorbed photons generate electricity.
The energy of a photon is transferred to an electron
in an atom of the semiconductor device. With its newfound energy,
the electron is able to escape from its normal position associated
with a single atom in the semiconductor to become part of the
current in an electrical circuit. Special electrical properties
of the PV cell a built-in electric field provide the voltage needed
to drive the current through an external load.
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