How do solar cells work?
Most solar panels today are silicon based. Silicon is one of the most abundant minerals on earth, and has some unique properties which make it a good candidate for converting sunlight into electricity!
A solar cell consists of two silicon ‘wafers’, each with its own purpose:
- N-type (negative) silicon has been treated with phosphorus. Phosphorus has one more electron than silicon, so when introduced to the silicon there is a “free electron” that wants to leave.
- P-type (positive) silicon has been treated with boron, which has fewer electrons than silicon. This creates “electron holes” – in other words, the p-type silicon wants to accept electrons.
This process of introducing impurities to a substance is called doping.
When photons strike the n-type silicon, this provides the free electrons with enough energy to be knocked free and move across to the p-type silicon. This flow of electrons is otherwise known as – you guessed it – Electricity!
Watch this short video for more info on how solar works: