Source: Energy & Management Powernews, June 15, 2022
Perovskite CIS tandem solar cells with an efficiency of almost 25% have been produced at the Karlsruhe Institute of Technology (KIT). Their shape makes them exciting.
Perovskite solar cells have undergone a steep development over the past decade. In combination with copper indium diselenide (CIS), researchers have now achieved a new efficiency record with perovskite solar cells, KIT reported. An international team in Karlsruhe has now succeeded in producing perovskite-CIS tandem solar cells with a peak efficiency of 24.9%.
Although there are solar cells with a definitely higher efficiency, the new material combination has its advantages, KIT says: perovskite-CIS tandem solar cells stand for lightness and versatility, "so that the use of these tandem solar cells is also conceivable on vehicles, portable devices, and foldable or rollable devices."
It is known that stacking solar cells increases efficiency. Perovskite solar cells are ideal as a component of such stacks thanks to their versatility. For example, tandem solar cells made of perovskites and silicon have achieved record efficiencies of over 29%.
Additional advantages are promised by combining perovskites with other materials, such as copper indium diselenide (CIS) or copper indium gallium diselenide (CIGS). This makes flexible and lightweight tandem solar cells possible, which can also be used on curved surfaces.
To produce an efficient tandem perovskite solar cell, perovskites with a high bromine content are usually used, according to KIT. However, this often leads to voltage losses and phase instability. Since the KIT researchers and their partners use narrow bandgap CIS solar cells for their tandems at the bottom, they can make the top solar cells from perovskites with low bromine content, making them more efficient and stable.
Author: Stefan Sagmeister