1. S OLAR P ANELS Generating Electricity from the Sun 1

2. T HE S OLAR P ANEL 3 Main parts 1. N - Layer N for Negative 2. P - Layer P for positive 3. Electrical contacts 2

3. T HE E LEMENTS OF THE S OLAR P ANEL Silicon 4 outer electrons Electrons like to pair off Si Silicon – silicon bonds are strong and stable An electron is a negatively charged particle 3

4. Si 4

5. T HE E LEMENTS OF THE P ANEL Phosphorus – an Impurity 5 outer electrons Can be forced to bond with silicone Electrons like to be in pairs Si Silicon – phosphorus bonds sometimes have a free electron that is easily released P 5

6. SiP P P P P P P P P P P PP P PP P PP P P PPP N – Layer Silicium Extra electrons  Negative Charge 6

7. T HE E LEMENTS OF THE P ANEL Boron – Another Impurity 3 outer electrons Can be forced to bond with silicone Electrons like to be in pairs Si Silicon – Boron bonds are weaker and tend to have holes in the crystal structure B 7 These holes attract free electrons

8. SiB B B B B B B B B B B BB BB BBB B BBB B P – Layer Silicium Missing electrons  Positive Charge 8

9. P-Layer N-Layer T HE E LECTRIC F IELD When a N-Layer is near a P-Layer it creates an electric field between them When energized, electrons will move across the field Electric field Sunlight (Energy)

10. P-Layer N-Layer Sunlight (Energy) Electrical Contact (wires)

11. Real electrons move 1000000x faster 11

12. 12

13. 13 Questions?