Large‐Area Perovskite Film Prepared by New FFASE Method for Stable Solar Modules Having High Efficiency under Both Outdoor and Indoor Light Harvesting

Abstract

High-quality perovskite film is deposited on a 30 cm × 40 cm LiCoO 2 -coated ITO/glass via newly developed freely falling anti-solvent extraction (FFASE) method followed by post watervapor annealing in an ambient atmosphere. Perovskite solar modules (PSMs, active area of 25.2 cm 2 with mask) based on this high-quality film achieve the highest efficiency of 16.04 and 30.76% under 1 sun (100 mW cm −2 ) and 945 lux fluorescent light illumination, respectively. The encapsulated PSMs are stable at −20 to 80 °C thermal cycling and keep high efficiency at temperature as low as −20 °C and as high as 80 °C. When the encapsulated PSM is heated at 85 °C and 85% relative humidity under room lighting or heated at 60 °C under AM1.5 (100 mW cm −2 ) illumination for 1000 h, loses only ≈8% of its original efficiency. The high stability of PSMs is due to very high quality perovskite absorber being used. The underlying concept of the FFASE method for extracting the solvent from the large-area perovskite precursor film is that the whole precursor film contacts with the fresh anti-solvent during the crystallization stage.

Large‐Area Metal Halide Perovskite Photovoltaics Based on Solvent Bathing and Solution Bathing

“…In addition, from the mechanical point of view, C. H. Chiang et al [38] studied the change of extraction rate of precursor liquid film by antisolvent bathing under free fall process (FFASE), as shown in Figure 4i. The FFASE process specifically means that the substrate coated with the precursor liquid film falls into a solution bathing at a certain free-falling height through a built track and "dips" at the same time, that is, during the whole free-falling soaking process, the precursor liquid film can contact with a "fresh" antisolvent, which avoids the accumulation of polar solvents such as DMF, DMSO, and NMP extracted from the antisolvent near the nucleation site of the film and reduces its interference to the nucleation and growth of perovskite films.…”

“…It should also be noted that the selected solvent needs to have a suitable boiling point, which will be beneficial to broaden the preparation process window. [23] Because mixed cation and mixed halide perovskite has better resistance to damp and heat than MAPbI 3 , C. H. Chiang et al [38] chose FAI, PbI 2 , MABr 2 , and PbBr 2 as perovskite materials. As shown in the SEM image of Figure 5d, the surface morphology of the film prepared in the mixed solvent of gamma-butyrolactone (GBL) and 2-pyrrolidinone (2P) with a ratio of 4:1 is the best.…”

“…From the mechanical point of view, C. H. Chiang et al [38] used FFASE to explore the relationship between the extraction rate of antisolvent for perovskite precursor liquid film and the final preparation of high-quality large-area perovskite films. The FFASE method suggested that the perovskite precursor liquid film could be placed on a holder with a track and let it fall freely into an antisolvent bathing for soaking.…”

“…From the mechanical point of view, C. H. Chiang et al [38] studied the change of extraction rate of precursor liquid film by antisolvent bathing under free fall process (FFASE). In addition, they also emphasized that the different solvents of perovskite precursor solution will have a certain influence on the morphology of perovskite thin films.…”

“…d) SEM images of perovskite precursor prepared by four different solvents, respectively. Reproduced with permission [38]. Copyright 2023, Wiley.…”