Perovskite crystal solar panels

By Mariusz Bogacki, Researcher and Science Communicator, Edinburgh

Solar energy is one of the most popular and fastest-growing types of renewable energy. This shouldn’t come as a surprise, as the daily input of solar energy to the earth’s surface is enough to fulfil our energy needs multiple times over. The problem however, lies in converting it using cheap, efficient and environmentally friendly technology. A breakthrough in the development of Perovskite crystals promises to do just that!

Solar energy
In order to convert solar energy into electricity, most of today’s solar panels utilise crystalline silicon as a semiconductor. The efficiency of a solar panel is determined by the amount of energy a semiconductor can capture from a photon (a particle that transmits light). Crystalline silicon has proven a reliable material capable of withstanding long exposures to adverse weather conditions, offering a wide range of applications. Current silicon solar cells are able to convert approximately 22% of the available solar energy into electricity. Unfortunately, scientists agree that this is its efficiency limit. Many believe that Perovskite crystal holds the solution to this limitation.

Perovskite
Perovskite is a term given to a material with the same crystal structure as the mineral calcium titanium oxide – discovered by a Russian mineralogist Lev Perovski in the late 19th century. In the solar energy industry, Perovskite refers to a thin, flexible and lightweight crystal structure that can be combined with silicon in order to increase the performance of a solar panel. Such ‘tandem’ solar cells can reach a peak efficiency of 29.1% with a theoretical limit of 43%. Given that the research on the application of Perovskite into solar panels is only about a decade old, this is a hugely promising discovery. What’s more, the manufacturing process is not energy-intensive and reduces material waste, thus decreasing the cost of solar panels. It is therefore hoped that these cheaper, more efficient panels will generate more demand for solar energy among customers.

Potential applications
While the ‘tandem’ solution is looking like the most viable application of Perovskite, the material could be used in many other products. Tests have begun on coating a variety of plastic materials with thin Perovskite films in order to create lightweight and flexible products. Although less efficient, these devices could be installed on top of cars, boats or airplanes. In fact, Perovskite films could be applied to rollable photovoltaic blinds or even sails that double as solar panels. For now however, it remains unclear whether Perovskite films will be durable enough to function for the 25 years that silicon panels do.

The future is bright!
Reducing the cost of production and materials used for solar panels is not only good for the consumers, but perhaps more importantly for the environment. Apart from driving down the cost of its products, manufacturers of solar panels are working towards making the production of green energy greener. Such philosophy promises a bright future for the industry and society as a whole.