A group of researchers at Kaunas University of Technology fabricated materials that were used to build an exemplary perovskite solar module displaying an efficiency of 21.4 percent. This was achieved by making the active solar cell layer passive, which amplifies the efficiency of the cell and improves its stability significantly.
Perovskite solar cells today is one of the fastest developing solar cell technologies. Structurally, perovskite solar cells are lightweight, thin-layered, flexible, and are made of low cost materials. However, this model of solar cell faces a key challenge: Quick degradation of perovskite material under environmental conditions.
Meanwhile, pacifying of solar cell layer is a simple yet effective means to improve the stability of perovskite cells and has been considered as one of the most useful strategies to remove the defects of perovskite materials and their downsides. This results in passivated perovskite surface to become more resistant to ambient conditions as temperature or humidity, and more stable to extend the durability of the device.
The work of KTU chemists along with researchers from some other academic institutions has led to significant improvement in the stability of perovskite solar cells using passivation. The method leads to chemically inactivity of the perovskite surface during passivation thereby removing the defects of perovskite that occur during manufacture. The resultant perovskite solar cells attain an efficiency 23.9 % with long term operational stability.
In fact, passivation has been used earlier, with a 2D layer of perovskite formed on the traditional 3D perovskite light absorber so far. This makes it difficult for carriers to move, in particular at higher temperatures. This is critical to avoid to prevent solar cells from becoming hot.