How Silicon Wafer Based Solar Cells Are Made

Many people are looking towards solar power as a way of generating plenty of electricity without causing any pollution. The energy needs of the world's population are growing on a daily basis. But have you ever wondered how these solar cells are made, and what makes them work?

Most of the solar cells that are popular these days are poly-silicon cells. This is the type of cell which is used in homes and even in portable applications such as on motor homes and when camping. One solar cell does not produce a whole lot of electricity, however when they are connected together they can produce a substantial amount of electricity.

When making silicon wafer based solar cells the first thing that happens is that the silicon is prepared. The majority of cells are made using silicon dioxide. This will first be heated using a furnace which makes it pure. The silicon needs to be 99.5% pure in order to make cells.

When the silicon is purified it is then crystallized. To do this the silicon is melted and another material is added such as Boron. This is the positive charged element of the solar cell.

The silicon is then cut into very thin wafers using specialist machines. These are normally 200-300 microns thick. Once the wafers are cut they are cleaned.

Now the cells will be constructed, the cells will be put into a negative charge solution, and a layer will be added to prevent reflection. Conductors made out of silver or aluminum is then added to the cells so that they can be connected.

The cells are then organized into solar panels; they are put onto a sheet and all connected. Glass is then put over the top to provide protection and the sides are framed. At this point your silicon wafer based solar cells are ready to be used!

A single solar cell is not very powerful; on average they produce only half a volt. However when connected together they can produce useful amounts of energy. The problem with solar cells is the efficiency; poly-silicon cannot convert all of the light into energy only around 10% of the energy is converted into electricity. Over time the technology of the panels should improve and so should the efficiency.