New solar cell design cuts 90% defects, sets 2D/3D perovskite record

Researchers at the Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, have developed a novel buried-interface engineering strategy that significantly enhances the efficiency and durability of perovskite solar cells. By modifying tin dioxide (SnO₂) nanoparticles with thioglycolic acid (TGA) and oleylamine (OAm), they created a multifunctional electron transport layer (SnO₂-TGA-OAm) that triggers the formation of an ultra-thin two-dimensional (2D) perovskite layer exclusively at the buried interface during thermal annealing. This targeted approach suppresses interfacial defects by over 90% without affecting the bulk crystal structure, overcoming limitations of previous methods that indiscriminately formed 2D phases throughout the film. The new design achieved record power conversion efficiencies of 26.19% in small-area devices (0.09 cm²) and maintained high efficiencies in larger modules—23.44% for 21.54 cm