In recent years, independent perovskite cells have made rapid progress in conversion efficiency, and some cells have reached efficiencies of 25% or higher. So far, many cutting-edge R&D technologies have selected n-type or n-i-p cell structures for the perovskite layer.

However, when it comes to making a series connection of perovskite and silicon-based bottom cells, the nip structure faces major challenges. Many researchers turn to pin structures because in some of the most promising perovskite studies, the nip structure will be connected in series. The removal of components will produce undesirable side effects.

However, a research team composed of King Saudi University of Science and Technology (KAUST) has overcome several of these challenges. They demonstrated a tandem cell based on n-i-p perovskite superimposed on a silicon-based heterojunction cell, with an efficiency of 27%. This is a big leap from the previous record of 22%.

This result was published in "Energy and Environmental Science", the paper titled "Ligand-bridged charge extraction and enhanced quantum efficiency enable high-efficiency nip perovskite/silicon-based tandem solar cell with enhanced quantum efficiency. efficient n–i–p perovskite/silicon tandem solar cells)”. The team studied a material called amorphous niobium oxide, which produces selective contact, which limits the total amount of light energy absorbed by the cell and manifests itself in the form of loss of heat energy.

Erkan Adin, a researcher at King’s University of Science and Technology, explained: “In general, we allow conventional resultant tandem cells to capture more light, and, thanks to our newly developed contact material, the absorbed energy will be converted into more efficiently Electricity. Based on these technologies, we have achieved a cell conversion efficiency of over 27%."

After overcoming these basic challenges, the King's University of Science and Technology research team is expected to use n-i-p tandem cell technology to achieve higher conversion efficiency. At the same time, they also pointed out that this cell has great potential in hydrolysis-photovoltaic hydrogen production. The next step of the research team will be to expand the size of the cell to achieve a full-size 6-inch silicon wafer to prepare the cell. At present, the team has applied tandem technology to double-sided heterojunction cells, and is at the leading level in the industry.