Solar Cells

What is a solar cell?

Generates electricity Uses light/ photons Photovoltaic Effect Makes up solar panels Average output 17.2V, 60W (at 3.5

A)

Photovoltaic Effect

Similar to phototelctric effect But electrons are not actually emitted Raised to higher energy levels (excitation) Generates electricity

• Silicon makes bonds with 5 other silicon atoms to form its crystal structure

• One can be replaced with boron (P-type)

• Or, one can be replaced with nitrogen (N-type)

• Boron gives an extra electron • Multistructure cells

What are solar cells used for?

Energy production To power things from houses

and buildings, to the Hubble telescope, and Mars Rover.

People who have their own solar panels often produce a surplus of electricity, and can sell it back to the National Grid.

Stats about solar energy

Up to 4% of Britain's energy can be produced by solar panels by 2020.

The amount of solar energy that hits the Earth in one hour can provide energy for the world’s population for a year.

Einstein's Nobel prize was for his work on photovoltaics.

Method

Set up experiment Measure current and voltage for a

range of positive and negative values

Conduct experiment in light and dark Power = IV Power supplied by solar cell is

difference in powers from two experiments