Polymer 'Armour' Fortifies Next-Generation Solar Cells

Perovskite solar cells hold great promise for the future of renewable energy, especially when layered in high-performance 'tandem' configurations. However, the crucial wide-bandgap perovskite component has long been hampered by poor stability and energy losses.

A common approach to fix this is to create a 3D/2D perovskite 'heterojunction'—a specialised layered structure—but the interface between these layers has remained a weak point.

Now, scientists have engineered a novel solution: a custom cross-linked polymer. This ultra-thin film is deposited at the critical interface, where its chemical groups patch surface defects and reduce material strain. This creates a smoother energy pathway and minimises waste.

Crucially, the polymer’s skeleton also acts as a physical barrier, halting the movement of volatile ions that cause degradation under heat. This dual-action approach resulted in tandem cells with a certified efficiency of 27.29% and exceptional thermal stability, pushing the technology closer to real-world application.