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Hi I’m Rio Small Alternative energy is important for everyone’s
future, from scientist to business people, to anyone who uses electricity.
Our society consumes huge quantities of fossil fuels to fulfill our energy needs. At our
current rate, we will deplete our scarce resources and overheat our planet unless we find other
sources of energy and fast. One of the most promising options is solar
energy. Unlike fossil fuels, sunlight is free, abundant and sustainable, and can be converted
directly into electricity by solar cells. The first generation solar cells are silicon
solar cells formed from thin silicon wafers that act as a semi-conductor, transporting
electrons excited by light through an electric field.
Silicon solar cells are relatively efficient and reliable yet the silicon wafers are expensive
to make and purify and the resulting cell is rigid and brittle.
In recent years, research has produced a dye sensitized solar cell that uses organic dye
instead of silicon to absorb light and initiate the flow of electrons, the dye is similar
to the bright green chlorophyll plants use to make food from sunlight. The cells are
inexpensive to make, and can be bendable and thin but they are not as efficient as silicon
cells and dry out when exposed to air and sun.
An ideal solar cell would be efficient, reliable, cost effective and flexible. Further research
will develop third generation solar cells that combine the best of silicon and dye sensitized
cells. This lab shows how to make a simple dye sensitized
solar cell using, of all things, berry juice, to capture light and initiate the flow of
electrons. The cell takes about 3 hours to assemble and will produce about 0.4 volts
of electricity. This experiment shows how easy it is to mimic
photosynthesis by using a natural dye to capture sunlight and convert it to energy in a form
we could use.