Binary antisolvent bathing enabled highly efficient and uniform large-area perovskite solar cells

Mixed Solvent Engineering for Morphology Optimization of the Electron Transport Layer in Perovskite Photovoltaics

“…As per the S–Q limit model, the theoretical PCE in single junction PSCs is ∼33%; however, at the experimental level, there are several factors responsible for efficiency loss in OIHPSCs. , Additionally, the morphologies of the OIHP and transport layers play crucial roles in the PSC performance. − The morphology of photo-absorbers is generally related to the light-harvesting and charge carrier generation in PSCs. For boosting PCE in PSCs, there has been broad research going on to fabricate controlled perovskite films with uniformity through solution processing that includes solvent vapor annealing, sequential depositions, and solvent engineering. ,,− In conventional PSCs, the photo-absorber is sandwiched between the electron transport layer (ETL) and hole transport layer (HTL), where TiO 2 typically is employed as an ETL; however, the high temperature processing for its crystallization and sintering could increase the overall production cost and hence the commercialization. , To overcome this issue, an inverted p-i-n PSC structure has been developed and under extensive research, where organic ETLs such as PCBM are exploited, help in minimizing the density of defects in the perovskite/ETL interface, deliver a well-matched alignment of band structures, and so on. − Nevertheless, PSCs without ETL generally face substantial reduction in V oc , J sc , and FF and affect the overall device performance. − It is worth mentioning that the morphology of ETL and interactions between multiple interfaces within the device are very crucial for efficient charge transport and collection processes; ,, however, focused investigations on ETL morphology studies in PSCs are limited. There are few systematic studies that have been pursued on different mono-solvent systems followed with the prolonged solvent annealing process of ETL for complete evaporation of the solvent and better perovskite/ETL interfacing, resulting in controlled film quality with respectable efficiency. ,, Liu and Lee investigated the effect of 1,8-diiodooctane (DIO) as a solvent additive to control the PCBM-ETL morphology with an annealing temperature of 40 °C for 30 min in an inverted PSC architecture, achieving a PCE of 14.8%.…”

Air-processed MAPbI3 perovskite solar cells achieve 20.87% efficiency and excellent bending resistance enabled via a polymer dual-passivation strategy

“…Moreover, the trap state density ( N traps ) was estimated using the following formula:where ε , ε 0 , V TFL and L are the vacuum permittivity, relative dielectric constant, trap-filling limit voltage and thickness of the perovskite film, respectively. 40 It could be found that N traps impressively reduced from 3.83 × 10 15 cm −3 for the pristine device to 2.64 × 10 15 cm −3 for the APP-passivated PSC. These results demonstrate that both under-coordinated Pb 2+ and I − of the perovskite on the surface/grain boundaries could be passivated by APP (forming an impactful chemical reaction), reducing the defect state density.…”

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

“…In 2021, G. Jang et al [ 30 ] chose to add DE (diethyl ether) into EA (ethyl acetate) antisolvent bathing, and the crystallization kinetics of perovskite was effectively regulated and delayed by the binary mixed solvent bathing. Compared with a single antisolvent, the binary mixed solvent bathing inhibited the number of crystal nuclei and promoted the growth of larger perovskite particles after annealing.…”

“…In 2021, G. Jang et al [ 30 ] chose to add a small amount of ether (DE) to the ethyl acetate (EA) antisolvent to form a binary mixed solvent bathing for preparing high‐quality large‐area perovskite films and analyzed the influence of binary mixed solvent bathing on crystallization kinetics in the extraction process of the wet perovskite precursor film compared with a single antisolvent bathing. The results show that 1) when DE is added into EA solvent to form mixed solvent bathing, the miscibility between binary mixed solvent and precursor solvent decreases, which delays the crystallization kinetics of perovskite.…”