High-Spatial-Resolution and Energy-Efficient Laser-Induced Annealing for AlO x /SiN x Passivation in Back-Contact Silicon Solar Cells

High-efficiency back-contact silicon solar cells rely heavily on excellent front-surface passivation to minimize recombination losses, yet conventional thermal activation imposes a global thermal budget that results in an extremely high energy consumption. Here, we demonstrate a spatially resolved and energy-efficient laser annealing technique that utilizes spatiotemporal thermal confinement to selectively activate AlOx/SiNx passivation stacks. By driving a nonequilibrium kinetic activation process, this localized treatment significantly enhances the τeff from ∼2000 to 2760 μs. This improvement is attributed to the simultaneous reduction of Dit and the augmentation of Q tot, achieving passivation quality comparable to equilibrium furnace annealing with less than 1% of the energy consumption. Highlighting the potential for sustainable manufacturing, this technique was applied to fully completed hybrid integrated back-contact (HIBC) devices, establishing laser annealing as a generalizable, low-thermal-budget platform for precise defect engineering in advanced photovoltaic architectures.