Synergistic effect of additive engineering and ultrafast laser crystallization enabled efficient and stable air-processed perovskite solar cells

The growing renewable energy demands globally spotlighted photovoltaics (PVs), with a special emphasis on perovskite solar cells (PSCs). However, existing solution-processing techniques significantly rely on time consuming, and energy inefficient post-fabrication with high-temperature annealing which cause heat energy waste, thereby hindering their applicability. To address this issue, we proposed a synergistic effect of additive engineering and simple, energy efficient yet fast laser crystallization approach which produces high quality triple cation mixed halide (Cs0.05FA0.8MA0.2Pb(I0.85 Br0.15)3) perovskite films at ambient conditions by the precise regulation of perovskite composition and laser parameters. This method transforms as-deposited perovskite into perovskite photoactive phase (α-phase) within seconds as validated by X-ray diffraction analysis. The target device attained remarkable Power Conversion Efficiency (PCE) of ∼21 % at room temperature. In addition, our findings delve into the remarkable stability enhancement through combined effect of additive engineering and ultrafast laser crystallization, as the target device retained 90 % of its initial PCE after 1007 h placement in ambient conditions without any encapsulation. Thus, we propose that synergistic effect of optimized additive and laser crystallization has the potential to solve the issue of stabilizing perovskite at room temperature within seconds which will speed up the perovskite-based PV production for sustainable light harvesting.