Types of solar cells

Absorbing the sun

Materials and Solar Cells

All solar cells contain materials that absorb light resulting in the separation of charges, electrons and holes, that can then be extracted to do work. So the types of solar cells are characterised by these energy materials, typically semi-conductors.

Common solar cells are shown below:

• Silicon solar cell (Si) – there are a wide variety of silicon solar cells from the high performance but expensive crystalline to the much cheaper amorphous silicon cells.

• Cadmium telluride solar cell (CdTe)

• Copper indium gallium selenide solar cells (CI(G)S)

• Gallium arsenide germanium solar cell (GaAs)

The following solar cells are under commercial development, there is however still a lot of research taking place;

• Dye-sensitised solar cell (DSSC)

• Organic solar cell (OPV)

• Perovskite solar cell

We will look in more depth at a dye-sensitised solar cell later in this course.

Terawatt Challenge?

When we think about the Terawatt Challenge, we need to consider a couple of important points about these technologies:

Firstly, how good are they at turning the sun’s energy into electricity for us to use? Are the materials abundant enough to be produced at very large scale? And, of course, are they going to be easy to manufacture?

It turns out that none of these technologies can tick all the boxes, at least not yet. Organic (plastic-based) solar cells do have major advantages when it comes to these last two points, as plastics are typically made from readily available elements, and their flexibility makes them easier to manufacture at high-volume and high-speed.

• What type of solar cell do you find most interesting?
• Which type has the most potential for future application?