Perovskites are a class of materials that have a cube-like and diamond-like crystal structure. Though the first perovskites were discovered more than 180 years ago, they were only applied to solar cells within the last two decades. They work the same way other semiconductor based cells do; light from the sun excites electrons in the material, and those electrons flow to conducting electrodes and generate a current. In 2006, perovskite cells were about 3% efficient. Fast forward to 2020, and some researchers were boasting 25% efficiency. For comparison, the first silicon solar cells were created in a lab as far back as 1940. In the 80 years since then, they’ve matured steadily to the point where they are now typically 15-20% efficient. But while silicon cells are getting cheaper all the time, they’re still relatively expensive and difficult to make. Perovskite cells, on the other hand, can be made with simpler manufacturing processes like printing the crystals onto a surface, so they have the potential to be much cheaper.
