High Efficiency over 20% of Perovskite Solar Cells by Spray Coating via a Simple Process

Abstract

The development of perovskite solar cells (PSCs) has progressed rapidly because of their high efficiency and low cost. The performance of PSCs is predominantly determined by the quality of the perovskite films, which is controlled by the fabrication process. The comprehensive and in-depth understanding of the nucleation, crystallization, and growth process are imperative for the further advancement of large-scale manufacturing of high-quality perovskite films. In this work, the simple process parameters of perovskite thin films were systematically optimized at ambient air, such as containing the thickness of the perovskite thin film, the anti-solvent bath, and the thermal annealing time. Through these simple processes, the wet film, solvent volatilization, and crystallization of perovskite films can be controlled and optimized. After optimizing the spraying conditions, the champion power conversion efficiency (PCE) of the PSCs achieved 20.6% (reverse scan) and had little hysteresis in the current density−voltage (J− V). In addition, the unsealed device retained 85% of its original PCE and showed excellent long-term stability after 650 h of storage in the drying tower.

Gas‐Assisted Spray Coating of Perovskite Solar Cells Incorporating Sprayed Self‐Assembled Monolayers

“…Typically, this involves the use of an antisolvent during spin coating. [70] However, to trigger nucleation during or after spray coating, researchers have also used an antisolvent bath method, [29,71] although the scalability of this processes is limited by the use of significant quantities of solvent that becomes gradually "contaminated" during any device run. Alternative approaches to induce supersaturation include thermal annealing, [72] vacuum-assisted solution processing, [73] hotair blowing, [74] and plasma-treatments.…”

“…However, the performance of spray-fabricated PSCs and modules has not yet matched those prepared by other scalable techniques. [27,28] For example, state-of-the-art spray-cast PSCs presently exhibit PCEs of only around 20% and have required postdeposition treatments which may limit their potential for roll-to-roll processing, such as submersion into an antisolvent bath [29] or exposure to a vacuum to induce supersaturation. [30] Furthermore, dewetting effects can occur during spray-deposition, which generate morphological defects and limit the performance of large-area spraycoated PSCs.…”

Alkali Additives Enable Efficient Large Area (>55 cm2) Slot‐Die Coated Perovskite Solar Modules

“…[ 3 ] Spin‐coating is most commonly used for highly efficient PSCs, [ 1c,4 ] which is far from ideal for industrial manufacturing. Thus, several scalable coating techniques have been developed, [ 5 ] such as spray deposition, [ 6 ] slot‐die coating, [ 7 ] inkjet printing, [ 8 ] screen printing, [ 9 ] and blade coating. [ 10 ] Among these scalable techniques, slot‐die coating method is especially promising, owing to its compatibility with the roll‐to‐roll or sheet‐to‐sheet fabrication process.…”

Binary Additive Engineering Enables Efficient Perovskite Solar Cells via Spray-Coating in Air

“…23 Cai et al employed a diethyl ether bath to treat the spray-coated wet film to control the nucleation of perovskite, therefore fabricating the device with the highest efficiency of 20.6% for spray-coated PSCs at present. 32 Although these approaches are effective, they all introduced an extra step after the spray-coating process and increased the complexity of device fabrication, therefore weakening the advantage of continuous mass production of spray-coating.…”