Control over atomic structure of perovskites could transform solar cells

Researchers have developed a novel vapor-based method to grow ultra-thin halide perovskite films with atomic-level precision, potentially transforming the fabrication of solar cells, LEDs, lasers, and quantum devices. Unlike traditional solution processing, which is difficult to control and messy, this vapor deposition technique—commonly used for standard semiconductors—enables precise alignment of atoms in both two-dimensional and three-dimensional perovskite layers. This epitaxial growth approach allows for fine-tuning of the material’s properties by controlling the thickness and composition of each layer down to fractions of an atom. The team demonstrated the ability to engineer the junctions between perovskite layers to either keep electrons and holes together or separate them, significantly impacting light emission efficiency. They achieved tunability of the energy difference between layers by more than half an electron volt and extended charge carrier lifetimes to over 10 microseconds, far exceeding typical values. This unprecedented control opens avenues for scalable, high-performance optoelect