We have already discussed on occasion that perovskite solar cells are a cheap alternative for manufacturing solar panels and that they could be a good substitute for silicon to manufacture them. Now researchers have improved the stability and efficiency of perovskite solar cells using a layer of Quantum Dots.
Perovskite solar cells have come a long way in a short time, but there is still room for improvement. The latest innovation that engineers have added to get the most out of this mineral, in order to make solar cells with it, is a layer of Quantum Dots. This results in a much more stable solar cell with near-record efficiency . Spain is a country where we can enjoy many hours of sunlight per year, which makes it an ideal place to get the most out of solar energy through the installation of solar panels that take advantage of the sun’s energy, and thus achieve a self-consumption that generates little impact on the environment, in addition to allowing us to save in the short and long term by reducing the amount we pay on the electricity bill.
perovskite solar cells
Perovskite makes solar cells more effective and makes solar panels more efficient for several reasons. Its thin film is capable of absorbing the entire spectrum of visible light , as well as being cheap to manufacture, lightweight and flexible. There are many different perovskites resulting from different combinations of elements, but one of the most promising is the formamidinium (FA)-based FAPbI3 crystal.
But not everything was going to be advantages. Perovskite solar cells have stability problems and can degrade in adverse atmospheric conditions. In previous studies that we will explain below, scientists have tried to improve its stability by adding old pigments, 2D additives, chili compounds and bulky molecules.
Quantum Dots the key to greater efficiency
In a new study, researchers from EPFL and the Korea Energy Research Institute tested adding a new ingredient: Quantum Dots. A kind of nanoscale sized semiconductor crystals or particles used for their optical properties . Depending on their size they emit light of a different color. Quantum Dots are already being used in televisions and are now being tested in solar cells as well.
In their current study, published in the journal Science , the team used Quantum Dots made from a type of tin oxide to serve as the device’s electron transport layer. This layer transports electrons produced by the perovskite to the electrode, so the energy can be used.
The usual material used to make this layer is titanium dioxide, in comparison, the Quantum Dots improve the device’s ability to capture light , in addition to reducing an effect that sometimes occurs between the two layers and that is the causing the efficiency of the solar panel to be reduced.
Following the study, the team found that perovskite solar cells coated with Quantum Dots achieved efficiencies of up to 25.7% , just 0.1 shy of the current record set for a 0.08-cm cell. The efficiency achieved for larger solar cells was also good, achieving an efficiency of 23.3% for a 1 cm cell or 20.6% for a 64 cm cell. In any case, the researchers will have to continue working in order to solve the stability problems that perovskite has.