However, the impressive high PCE was obtained from small area cell (<1 cm 2) using non-up-scalable spin coating method in nitrogen. [1-3] To make commercially viable PSC, the development of low cost and large area fabrication process in ambient air is imperative. Many processes are available in industry for largescale area coating such as dip coating, blade coating, and slot-die coating, etc. Among them, the slot-die coating is preferable because the precision control of coating thickness and solution usage (i.e., minimum wastage of material). [4-7] The slot-die coating is also suitable to be adopted for continuously process which can reduce the cost of manufacturing even further. High performance PSC has been fabricated by scalable process such as blade coating, slot-die coating and spray coating. [8-14] However, most of studies concentrated on the perovskite layer processing in controlled environment. Only limited reports are on the scalable process operated in ambient air. [15-18] The commonly used architecture of p-in PSCs contains four layers deposited by solution process, and those four layers include hole transport layer (HTL), light absorption perovskite layer, electron transport layer (ETL) and work function modifier layer (WFL). First, all the solvents used in the processing of each layer should be nontoxic for the scalable process. [19-21] Then the balance among suitable chemical composition of each layer, solvent type, film morphology control, compatibility between layers, the stability of each layers to have a workable ambient air processing system is quite challenge in terms of science and engineering. The film morphology and compatibility of each layer of PSCs are controlled by the chemical compositions of each layer and processing condition. For the perovskite layer, the film morphology is determined by the kinetic rate of solvent evaporation and crystallization. [22-23] For spin coating, most of the solvents are removed rapidly by the coater rotation and the anti-solvent dripping. [24] However, the rate of the solvent evaporation of slot-die coating is lower than that of spin coating. [17,25-26] The strategies such as anti-solvent bath, gas quenching and pre-heat substrate method are adopted to increase the rate of solvent evaporation. [11,27-31] Although the high PCE devices can be achieved, the results are only performed on small-area substrate. If the Currently, high-efficiency perovskite solar cells are mainly fabricated by the spin-coating process, which limits the possibility of commercial mass-production of perovskite solar cells. In this work, the slot-die coating process is combined with near-infrared irradiation heating to quickly manufacture perovskite solar cells in air. The composition of the perovskite precursor solution is tuned by adding n-butanol, with its low boiling point and low surface tension, to increase the near-infrared energy absorption, facilitate the evaporation of the solvent system and film formation, and accelerate the crystallization of perovskite. High-quality uni...

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In article number 2001567, Yu‐Ching Huang, Wei‐Fang Su, and co‐workers demonstrate a facile process for the mass‐production of perovskite solar cells. The process integrates slot‐die coating and near‐infrared irradiation heating techniques, combined with a new perovskite precursor formula to rapidly produce large‐area perovskite solar cells and modules in air.

Large‐area perovskite solar modules fabrication has been demonstrated with a rapid process of large‐area slot‐die coating, drying, and crystallization using near‐infrared radiation in ambient air, in which the laser‐scribing process is applied to fabricate the modules. However, defective coating of perovskite layer near laser‐scribed P1 line which isolates the front electrode of transparent conductive oxide (TCO) results very low module efficiencies. Therefore, systematic study is conducted to investigate the root cause, mechanism and solution of the defective coating and crystallization of the perovskite layer. Scanning electron microscope, energy‐dispersive X‐ray spectroscopy, and atomic force microscopy are used to characterize the TCO film before and after P1 scribing. It is found that P1 laser‐scribing process changes surface morphology of TCO at the area near P1 line, which decreases the surface wettability and results discontinuous coating of precursor solution near P1 lines. The absence of TCO material in the P1 trench induces nonuniform heating during NIR annealing step, which is verified by thermal analysis via numerical simulation. After tuning laser process recipes, a large module with an active area of 46 cm2 is fabricated with a power conversion efficiency of 7.2% and geometry fill factor of 93.8%.