A few months ago, researchers from the University of Alabama, Jackson State University and NREL reported high-performance perovskite solar cells (PSCs) fabricated using rapid photonic annealing (RPA) based on ultraviolet light-emitting diode (UV-LED) sources.
The schematic of thermal annealing (TA) and rapid photon annealing (RPA) annealing of SnO2 ETL and perovskite absorber. Image from: Small
This approach replaces conventional thermal annealing with a fast, energy-efficient, and layer-specific process that enables precise control of film crystallization within seconds. The resulting PSCs achieved a power conversion efficiency of 23.03% - the highest reported for optically annealed perovskite devices.
The UV-LED RPA technique employs selected wavelengths tuned to the peak optical absorption of each functional layer, allowing targeted annealing without affecting underlying films. For the FAMAPbI₃₋ₓBrₓ perovskite absorber, 365 nm irradiation enabled complete crystallization in only 7 seconds, producing films with high crystallinity, reduced defect density, and stable performance over extended operation. Devices retained over 80% of their initial efficiency after 1000 hours of continuous illumination at 55 °C and 30–60% relative humidity.
This UV-LED-based photonic annealing concept offers improved process control, energy efficiency, and scalability for large-area module fabrication. The technique also provides a practical framework for optimizing light dosage and exposure time to tune film quality, offering potential applications across all-perovskite tandem solar cells, light-emitting diodes, and photodetectors.
By enabling rapid, controllable, and substrate-compatible annealing, this study advances photonic processing as a viable route for scalable manufacturing of perovskite photovoltaics.
