Slice and dope your silicon crystals

Slicing an egg with an egg slicer is much like the process that happens when a solar cell is manufactured. Each slice of silicon is then called a "wafer."

We now need to create a p-n junction in the wafer; to do this phosphorus is diffused into the surface of the silicon. Dip your egg into some food coloring or beetroot juice, and you will see that the juice covers one surface of the egg slice. Now, imagine that slice of egg were a solar cell, with the beetroot-soaked face pointing toward the light. Imagine an electrical contact on either side of the egg slice is connected to our circuit. The photons

Figure 10-10 Slicing silicon.

Figure 10-8 Growing silicon crystals.

Figure 10-10 Slicing silicon.

hit the colored side, which is "doped" with phosphorus to produce some extra electrons. By giving these electrons additional energy from the photons, they are able to "jump" the gap, across to the "boron" doped silicon (the plain old egg) where they fill the "holes" where there are electrons missing from the atomic structure. With a steady stream of photons, hitting the cell, a heavy stream of electrons are encouraged to migrate across the p-n junction, then travel around the circuit doing useful work!

Now these cells can be integrated into larger modules, or even arrays, to produce more power.

Figure 10-11 Doping with phosphorus.

Now we have looked at the technology of crystalline solar cells using silicon, let us turn our attention to thin-film solar cells.

Getting Started With Solar

Getting Started With Solar

Do we really want the one thing that gives us its resources unconditionally to suffer even more than it is suffering now? Nature, is a part of our being from the earliest human days. We respect Nature and it gives us its bounty, but in the recent past greedy money hungry corporations have made us all so destructive, so wasteful.

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