High-efficiency single-chip perovskite/perovskite/silicon three-junction solar cell

On December 28, 2023, the team of Xu Fuzong, Erkan Aydin and Stefanan De Wolf of King Abdullah University of Science and Technology (KAUST) in Saudi Arabia published an article entitled “Monolithic perovski” in the Joule journal te/perovskite/silicon triple-junction solar cells with cation double displacement enabled 2.0 eV per The research paper of ovskites. The researchers successfully prepared a tandem perovskite/perovskite/silicon triple-junction solar cell with an efficiency of 26.4% of 1 cm2, the highest level in the field.

Improving the power conversion efficiency of solar cells is essential to reduce the cost of photovoltaic cells and promote the transition to renewable energy. Multi-junction solar cells are favored for the more effective use of solar spectrum, especially the series perovskite/silicon two-junction laminated battery, which combines the mainstream silicon and perovskite in the market and has easy-to-adjust band gap, excellent photoelectric performance and potential low-cost batteries. The efficiency of its laboratory scale (~1 cm2) has reached 33.9%, exceeding the theoretical limit of single-junction batteries. However, its energy conversion efficiency can still be improved by introducing another absorption layer to form perovskite/perovskite/silicon triple junction battery, with a theoretical limit of 49.4%, which is higher than 45.1% of two-junction devices. However, this concept is limited by the lack of efficient and light-stable ultra-wide forbidden band (~2.0 eV) perovskite and system device design.

For ultra-wide forbidden-band perovskite, considering the efficiency and compatibility of the preparation process, the study adopted organic inorganic perovskite and modified it with synergistic additives: potassium thiocyanate (KSCN) and methylamine iodide (MAI), which significantly improves the efficiency of ultra-wide restricted perovskite monojunction battery to 15% (the forbidden One of the highest efficiency with width) and its light stability (almost 100% of the initial performance is maintained under a single sunlight for 300 minutes, while the control group only retains 21%). The synergistic additive was chosen because researchers discovered thiocyanide (SCN^–) for the first time, which is widely used in perovskite to improve the size of the grain. Without MA⁺, it will be limited to perovskite film to promote photophase analysis of the film. MA⁺ and SCN^– can form low-binding energy methylaminothiocyanate (MA-SCN), which evaporates perovskite films in the form of MA and HSCN gases at 100℃. This strategy eliminates the negative factors of SCN while improving the particle size of perovskite and improving the photoelectric parameters and stability of perovskite films. For the device structure, while giving the specific device structure, the author points out that the structure with ultra-thin gold as the connecting layer cannot be used in the three-node battery, because it is seriously absorbed in the light response area of the intermediate junction, which reduces the current of the intermediate junction battery, thus greatly limiting the efficiency of the three-node battery.

Finally, combined with the ultra-wide forbidden belt perovskite modified by collaborative additives and the battery structure designed by optical and electrical design, the researchers successfully prepared a 1 cm2tandem perovskite/perovskite/silicon three-junction solar cell with an efficiency of 26.4%, setting the highest level in the field and verifying the concept of three-junction batteries. The behavior has laid the foundation for future relevant research.

Related information: https://doi.org/10.1016/j.joule.2023.11.018