A Pressure-Assisted Fast Crystallization Strategy for Perovskite Solar Cells

The achievement of high-performance solar cell production hinges on the development of a reliable and effective approach for perovskite crystallization that is compatible with rapid and continuous processing on large substrates. Herein, a pressure-assisted fast crystallization technique is presented that reduces the thermal annealing period to less than 2 min and achieves the impressive formation of micrometer-sized vertical-monolithic perovskite crystals. The pressure-assisted technique provides confined space and pressure, where the confined space hinders the volatilization of residual solvents and enhances the Ostwald ripening effect. The presence of pressure provides internal energy for crystal growth, while the presence of solvent molecules accelerates solute diffusion. These factors collectively contribute to the rapid growth of grains. Results demonstrate that this pressure-assisted fast crystallization strategy significantly enhances the power conversion efficiency (PCE) of both n-i-p and p-i-n perovskite solar cells (PSCs), achieving PCEs of 22.80% and 24.69%, respectively. The improvement in PCE can be attributed to the reduced number of grain boundaries, minimized interfacial defects, and enhanced surface crystalline quality. Importantly, this approach is universal and highly reproducible for solution-processed manufacturing methods. It is anticipated that this efficient, reliable, and reproducible technique will accelerate the commercialization of PSCs.