Professor Yan Keyou's team at South China University of Technology published a research paper titled "Durable all-inorganic perovskite tandem photovoltaics" in the journal Nature. Dr. Duan Chenghao is the first author, and Professor Yan Keyou is the corresponding author.
Key Highlights: This paper employs a ligand evolution (LE) strategy with p-toluenesulfonylhydrazine (PTSH) to modulate film formation and eliminate deep traps in inorganic narrow-bandgap (NBG) perovskites, successfully developing 2T IPTSCs. As a result, the 1.31CsPb0.4Sn0.6I3:LE device delivers a record-breaking efficiency of 17.41%. Combined with a 1.92 eV CsPbI2Br top cell, the 2T IPTSCs achieve a record-breaking efficiency of 22.57% (certified 21.92%). Furthermore, the IPTSCs exhibit exceptional durability under maximum power point (MPP) tracking, maintaining 80% of their initial efficiency for 1510 hours at 65°C and 800 hours at 85°C, respectively.
Replacing organic cations (such as methylammonium (MA+) and formamidine (FA+)) with inorganic cations (such as Cs+) to prepare all-inorganic perovskites is an effective approach to improve the long-term photostability and thermal stability of perovskite solar cells (PSCs). Therefore, inorganic perovskite tandem solar cells (IPTSCs) hold promise for breaking efficiency bottlenecks and addressing stability issues. However, fabricating two-terminal (2T) IPTSCs remains challenging due to poor film formation and deep trap states induced by tin cations.
To address this issue, Keyou Yan's team at South China University of Technology developed a ligand evolution (LE) process from PTSH to p-toluenesulfonic acid (PTSA) to create high-quality, multifunctional Sn-Pb inorganic perovskites. The resulting CsPb0.4Sn0.6I3:LE PSCs achieved a record-breaking efficiency of 17.41%. Combined with a 1.92 eV CsPbI2Br top cell, 2T IPTSCs exhibited a world-class efficiency of 22.57% (certified 21.92%). Furthermore, the IPTSCs demonstrated exceptional durability under maximum power point (MPP) tracking, maintaining 80% of their initial efficiency for 1510 hours at 65°C and 800 hours at 85°C, respectively.
This study demonstrates that IPTSCs possess superior photothermal stability compared to HPTSCs. Optimizing the molecular structure for light-emitting diodes (LE) strategies holds promise for leveraging the performance and stability of perovskite tandems in the future. This study elucidates the diverse roles of LEs in the growth of inorganic NBG perovskites and is expected to provide insightful guidance for the development of efficient and stable IPTSCs.
Source：
https://doi.org/10.1038/s41586-024-08432-7 (2024)