Photoinduced halide segregation in wide bandgap (WBG) perovskites results in poor stability and limits their application in high-efficiency tandem solar cells. Yang Xudong and others from Shanghai Jiao Tong University reported a simple solution to achieve a photostable WBG perovskite solar cell (PSC ) with a band gap of ≈1.67 eV by ionically coupling potassium sorbate and burying defects at the perovskite interface.
Ion-coupled potassium sorbate (ICPS) enables controlled formation of N-methylformamidine ions, which can selectively passivate perovskite defects at grain boundaries, thereby enabling photohalogenation in perovskite films Material segregation is frozen under strong light. The single-junction WBG PSC achieved an energy conversion efficiency of 22.00%, an open circuit voltage (VOC) of 1.272V, and a photostability degradation of less than 2% during 2000 hours of operation.
In addition, the authors also fabricated a perovskite/silicon tandem solar cell with an efficiency of 30.72% (certified as 30.09%@1.087cm2). The packaged tandem device maintains 97% of its initial efficiency after 1,000 hours of operation.
Liang Qiao et.al Freezing Halide Segregation Under Intense Light for Photostable Perovskite/Silicon Tandem Solar Cells Adv. Energy Mater. 2023
DOI: 10.1002/aenm.202302983