Active Functional Groups and Adjacent Dual-Interaction Strategies Enable Perovskite Solar Cells to Prosper: Including Unique Morphology and Enhanced Optoelectronic Performance

Abstract

Excellent photoelectric properties entail perovskite solar cells with established position prevailing in the newgeneration photovoltaic landscape. However, the traditional solution preparation inevitably yields numerous defects, which eventually bloom ion migration and lead to the gradual collapse of perovskite. Here, phthalic acid (PHA) with adjacent carboxylic acid groups (−COOH) is used to passivate defects and regulate the morphology of perovskite films. Based on density functional theory (DFT) calculations, the two adjacent −COOH of PHA construct a dual interaction with the uncoordinated Pb 2+ of perovskite, thus significantly enhancing the passivation effect. Furthermore, the double-bonding interaction brought by PHA induces a unique surface-protruding morphology on perovskite films, which may act as a green channel for charge delivery, ultimately increasing the photo-generated current of perovskite solar cells (PSCs) to some extent. Under full-air preparation conditions, the PHA-optimized champion PSCs showed an efficiency of 20.02% with a boosted short-circuit current of 22.80 mA cm −2 , showing one of the best performances in all-air preparation until now. Meanwhile, PHA-PSCs exhibited brilliant stability. In short, this work provides some reliable and flexible guidance for the design of small-molecule additives.

2,2,2-Trifluoroethanol-Assisted Construction of 2D/3D Perovskite Heterostructures for Efficient and Stable Perovskite Solar Cells Made in Ambient Air

“…These results will lead to an increase in V OC in the device, which is also supported by the increased PCE of the device. To further 25,57 Due to the instability of perovskite materials, how to resolve the stability of the device is also an urgent issue. As shown in Figure 5a, we have normalized the parameters of unassembled IPA−PEAI-PSCs, TFE−PEAI-PSCs, and NBA−PEAI-PSCs.…”

“…The root-mean-square roughness ( R q ) of the 2D/3D perovskite layer after TFE–PEAI treatment is only 23.9 nm, which is much lower than the R q of the IPA–PEAI-perovskite film (28.5 nm) and the NBA–PEAI-perovskite film (32.7 nm). It is known that rough interfaces increase the trap density, therefore the post-treatment with TFE–PEAI will more effectively passivate this part of the defect trap. According to the SEM and AFM test results, the 3D perovskite films treated with IPA–PEAI and NBA–PEAI generated large unoriented 2D perovskite slices.…”

“…To simplify the preparation process and reduce manufacturing costs, all-air-processed PSCs have received much attention due to uninvolved well-controlled glovebox. − Unfortunately, the fabricating technique of high-quality 2D/3D perovskite heterostructures is very difficult to master, in particular, when the fabrication process is operated in an atmospheric environment with uncontrollable factors. , Therefore, only a few reports focus on such air-processed devices based on 2D/3D heterostructures so far, and a comprehensive study has been lacking.…”

Novel Two-Dimensional Graphdiyne-Derived Additive for Stable Inverted Perovskite Solar Cells

“…Not at all, defect-induced decomposition behavior aggravates the formation of perovskites, which could destroy the interfacial contact between the perovskite layer and charge-transporting layer. Therefore, preparing perovskite films with high crystallinity and few defects is a challenge to achieve high efficiency and good stability for PSCs …”

“…Therefore, preparing perovskite films with high crystallinity and few defects is a challenge to achieve high efficiency and good stability for PSCs. 13 For this purpose, researchers have put forward numerous passivation strategies to reduce defects in perovskite films, 14 including compositional engineering, 15 antisolvent additive engineering (AAE), interface engineering, and so forth. Among various methods to improve the quality of perovskite films, the AAE method has attracted much attention because of its low cost and simple operation process.…”