Solar panels could be set to get much more efficient in the near future thanks to materials that can be produced using the same cheap methods as silicon, whilst working more effectively.
Silicon is the semiconductor used in most panels as it is the most affordable to work with, despite the fact it will only convert about 10% of the sunlight it receives into electricity. There are a number of alternate semiconductors available that can offer a much higher conversion rate, however, most of these are simply too prohibitively expensive to be used en masse. However, materials known as perovskites may offer a solution.
When a semiconductor absorbs a photon, a negative electron is freed. As it moves it leaves behind it a positively charged hole, which is also capable of movement. The hole and the electron head off in separate directions through the structure of the semi conductor causing a current to flow. Perovskites have the same ability, but it was thought until know that the holes and electrons wouldn’t move very far and thus, not a lot of electricity would be produced.
Indeed, these materials have been used in solar panels for years, but not as semicoonductors. Until now they’d been used merely to absorb photons and then pass them onto a semiconductor. What’s more is that they had to be organised into a complex structure to achieve this end.
It’s now become apparent that they actually work better when used as a simple film, where they can convert electricity into sunlight as semiconductor with 15% efficiency. It’s thought that they could now contribute to the energy market at as little as a quarter of a price of silicon devices.
There could be drawbacks, however, and certain obstacles will need to be overcome before perovskites became the go to solar panel semiconductor. For instance, some persovkites have been known to degrade after prolonged exposure to ultraviolet sunlight, which is hardly ideal for a solar panel. In addition, the materials need to be demonstrably proven to be non toxic after being industrially processed which would drive up costs.