Question

What is a solar cell and how does it store energy?

Answer 1

A solar cell is an electronic device that catches sunlight and turns it directly into electricity. It's about the size of an adult's palm, octagonal in shape, and coloured bluish black. Solar cells are often bundled together to make larger units called solar modules, themselves coupled into even bigger units known as solar panels (the black- or blue-tinted slabs which you see in people's home—typically with several hundred individual solar cells per roof) or chopped into chips (to provide power for small gadgets like pocket calculators and digital watches).
A solar cell is a sandwich of n-type silicon (blue) and p-type silicon (red). It generates electricity by using sunlight to make electrons hop across the junction between the different flavours of silicon:
When sunlight shines on the cell, photons (light particles) bombard the upper surface.
The photons (yellow blobs) carry their energy down through the cell.
The photons give up their energy to electrons (green blobs) in the lower, p-type layer.
The electrons use this energy to jump across the barrier into the upper, n-type layer and escape out into the circuit.
Flowing around the circuit, the electrons make the lamp light up.