Multifunctional Passivation Strategy of Cationic and Anionic Defects for Efficient and Stable Perovskite Solar Cells

Abstract

The crystallinity of perovskite films is crucial for the performance and stability of perovskite solar cells (PSCs). Defects usually emerge in grain boundaries, leading to decomposition and non-radiative recombination of PSCs. Here, we present an effective additive engineering strategy to augment the long-term operation and stability of PSCs by doping a molecule with a symmetrical structure and bifunctional passivation, 2,5-thiophene dicarboxylic acid (TDCA), into the precursor solution. It is demonstrated that TDCA coordinates with the perovskite through hydrogen and Pb–O bonding, resulting in significantly enhanced crystallinity and defect passivation such as uncoordinated Pb2+ and I–. Meanwhile, the grain size is increased from 350 nm to about 650 nm for the perovskite, as well as the grain boundaries are reduced, which could inhibit the carrier non-radiative recombination loss. Consequently, the power conversion efficiency of champion PSCs is promoted from 19.31 to 22.78%. Furthermore, the enhanced crystallinity and defect passivation improve the wet-thermal stability of PSCs.

Multifunctional Organic Salt Regulated SnO2 Electron Transport Layer/Perovskite Interface for High Air‐Stable Perovskite Solar Cells

“…The diffraction peaks located at 14°, 18°, and 28° corresponded to the (110), (210), and (220) planes of PVK, respectively. [ 41 ] The diffraction peak at 12.5° with a strong peak intensity should be assigned to PbI 2 , and these moderate residues of PbI 2 could passivate the surface defects of PVK films. [ 42 ] The increase in characteristic peaks intensity of the PVK proves that the modification of SPS is beneficial to improve the crystallinity of PVK films.…”

Low‐Temperature Atomic Layer Deposition of Double‐Layer Water Vapor Barrier for High Humidity Stable Perovskite Solar Cells

“…[60] At the same time, the introduction of a water vapor barrier reduces the charge recombination loss between interfaces, improves the efficiency of carrier transmission, and improves the photovoltaic performance of the device. [53,61,62] XPS and UV-vis were used to study the elemental composition and chemical state of ALD SiAl x O y /SiO 2 . [63] We found that the optimized low-temperature ALD process did not cause any damage to the perovskite absorber layer.…”

Microregion Characterization of Grain Boundary Defects and Electron Capture of CsPbI2Br Perovskite

“…It is demonstrated that TDCA coordinates with the perovskite through hydrogen and PbÀO bonding, resulting in significantly enhanced crystallinity and defect passivation such as uncoordinated Pb 2+ and I À . [35] DOI: 10.1002/ente.202300907 All-inorganic CsPbI 2 Br perovskite solar cell shows superior thermal stability, but the power conversion efficiency falls behind organic devices, due to the existence of abundant defects. Halogen and metal ions at the grain boundaries induce the formation of defect states, which increases the probability of carrier recombination.…”

“…It is demonstrated that TDCA coordinates with the perovskite through hydrogen and Pb−O bonding, resulting in significantly enhanced crystallinity and defect passivation such as uncoordinated Pb 2+ and I − . [ 35 ] Therefore, TDCA can effectively passivate the defects of perovskite. Regarding the passivation mechanism, it is still unclear.…”