Toward All Slot‐Die Fabricated High Efficiency Large Area Perovskite Solar Cell Using Rapid Near Infrared Heating in Ambient Air

Abstract

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...

Substance and shadow of formamidinium lead triiodide based solar cells

“…In slot-die coating, a die is designed to have a thin channel to spread the perovskite ink to a flexible substrate. [94] Inject printing is a material efficient and contactless technique where a pressure pulse generated by a piezoelectric transducer in the continuous fluid supply controls the ejection of ink droplets to the moving substrate. [95] Moreover, spray coating has also been used for the fabrication of perovskite layers and this can be adapted as a future tool for fabrication of large area PSCs due to its wide atomisation possibilities.…”

Progress of Perovskite Solar Modules

“…A slot‐die coating method can take the overall advantage of the blade coating method due to the compatibility with a blade. [ 28–37 ] Figure a shows a schematic process of the slot‐die coating, where a perovskite precursor solution is supplied from a container to a slot‐die head with a given flow rate by a pump, where a formation of a steady‐state meniscus between the slot‐die head and the substrate is a key factor to obtain a homogeneous and defectless slot‐die‐coated perovskite film. [ 28 ] Similarly, the gas quenching can be used to control the solvent evaporation for fast crystallization by inducing the instant supersaturation.…”

Large-area perovskite films for PV applications: A perspective from nucleation and crystallization

“…To further shorten the annealing time, Huang et al developed a novel annealing process, named near-infrared irradiation (NIR) heating, which directly heated the substrate from the perovskite side [Fig. 7(c)], and shortened the annealing time down to a few seconds [17]. Different from using a hotplate which heats the substrate from the back, the NIR heat from the top, resulting in acceleration of perovskite conversion [Fig.…”

“…On the other hand, the conventional spin coating method, typically used for small cell fabrication has its challenges when applied for large-area (>1 cm 2 ) fabrication, such as poor uniformity, solution wastage, low throughput. To overcome these limitations, various techniques have been developed, including slotdie coating [13][14][15][16][17][18], spray coating [19][20][21][22], inkjet printing [23,24], blade coating [25][26][27][28]. However, technical problems, e.g.…”

“…Copyright 2020, The Royal Society of Chemistry. (c) NIR heating and the direction of thermal transfer transmission in hot plate heating and NIR heating[17]. Reproduced with permission from Ref [17].…”