A solar cell: is a device that converts
the energy of sunlight directly into electricity by the photovoltaic
effect (PV). Sometimes the
term solar cell is reserved for devices intended specifically to capture energy
from sunlight such as solar panels and solar cells, while the term photovoltaic
cell is used when the light source is unspecified. Assemblies of cells are used
to make solar panels, solar modules, or photovoltaic
arrays. Photovoltaics is the field of technology and research
related to the application of solar cells in producing electricity for
practical use. The energy generated this way is an example of solar energy.
The photovoltaic effect involves the creation of a voltage (or a corresponding electric
current) in a material upon exposure to electro-magnetic radiation.
Though the photovoltaic effect is directly related to the photoelectric effect, the two processes are different
and should be distinguished. In the photoelectric effect electrons are
ejected from a material s surface upon exposure to radiation of sufficient
energy. The photovoltaic effect is different in that the generated electrons
are transferred from one material to another resulting in the buildup of a
voltage between two electrodes.
Solar cells are devices which convert solar
energy directly into electricity, either directly via the photovoltaic effect,
or indirectly by first converting the solar energy to heat or chemical energy. The most
common form of solar cells are based on the photovoltaic (PV) effect in which
light falling on a two layer semi-conductor device produces a photo voltage or potential difference between the layers. This
voltage is capable of driving a current through an external circuit and thereby
producing useful work.
هذه المحاضرة يستفاد منها طلبة مشاريع التخرج للمرحلة الرابعة