High-Performance Annealing-Free Perovskite Solar Cells by a Simple Solution Post-Treatment Strategy

The annealing-free preparation strategy has progressed as an innovative approach for perovskite film fabricating, alongside accelerated production rate and reduced economic and time costs of perovskite solar cells (PSCs), thereby suggesting significant potential for commercial application. However, environmentally sensitive crystal properties of perovskite materials make it challenging to deposit an annealing-free perovskite film with enlarged grain size and uniform sur-face texture, leading to compromised device performance compared to the thermal-annealed device. To this end, we have proposed a facile crystal regrowth method in this work to promote the crystal quality and photo-electric parameter of annealing-free perovskite films through a straightforward post-treatment process. SEM images and XRD measurements indicated that excellent pinholes-free perovskite film with larger grain size and admirable crystallinity is obtained Via the introduction of post-treated technology. Meanwhile, UV-Vis spectra proposed that the post-treatment perovskite film exhibited better light absorption capacity especially in the wavelength range of 400-550 nm, this indicated that corresponding PSCs will achieve splendid photon-electron transfer capability and larger Jsc. PL, TRPL and TPV spectra all suggested that the post-treatment sample demonstrated suppressed charger recombination and optimized carrier transport property. The optimized champion device has achieved a superior power conversion efficiency of 22.50%, and the unencapsulated device could still maintain 86.10% of its initial efficiency after being stored in an atmospheric environment for 30 days.