Balancing the supersaturation rate and coordination capability for upscaling high-performance perovskite photovoltaics

Abstract

Transferring the well-established perovskite ink formulations from antisolvent spin coating to scalable deposition techniques remains a great challenge, primarily owing to the strikingly different crystallization kinetics involved in the two processes. Here, we discover that a balanced trade-off between supersaturation rate and coordination capability plays an essential role in regulating crystallization kinetics of the perovskite films deposited by scalable methods. In comparison to the commonly used DMF/DMSO solvent mixture, incorporating a small volume of NMP promotes rapid α-phase perovskite nucleation together with controllable crystal growth. Consequently, high-quality crystalline perovskite films with large grains and voids-free buried interface are readily obtained by blade coating. On these bases, inverted perovskite solar cells (0.09 cm2) and mini-modules (21.84 cm2) achieve high efficiencies of 25.38% and 23.22%, respectively. Furthermore, the unencapsulated solar cells deliver remarkable durability under maximum power point (MPP) tracking, maintaining 87% of their initial efficiency over 1000 h. This work provides an important avenue to bridge the gap between lab-scale cells to fab-scale perovskite photovoltaic modules.