GIST team demonstrates high-efficiency perovskite cells using modified SnO₂ layers

Researchers from the Gwangju Institute of Science and Technology (GIST) have reported a dual-function interface engineering method that improves both the efficiency and stability of perovskite solar cells. This approach involves incorporating polyethyleneimine into SnO₂ electron transport layers to enhance surface wettability and adjust the work function. The modification suppresses oxygen-vacancy defects, forms interfacial dipoles, and improves energy-level alignment, which supports efficient charge extraction and uniform perovskite crystallisation. Devices fabricated using the modified SnO₂ layers achieved a power conversion efficiency of 24.49%. Scalable minimodules with an active area of 24.8 cm² reached an efficiency of 22.56%. Stability testing showed that these minimodules retained 94% of their initial performance after 500 hours of operation. The modification process is solution-processable and compatible with ambient fabrication conditions. The findings were supported by advanced characterisation techniques and density functional theory calculations and were reported in Nano-Micro Small.