Search

Nickel oxide (NiOX) has a crucial role in enhancing the efficiency and stability of p‐i‐n inverted perovskite solar cells (PSCs), which hold great potential for commercialization. However, improving contact passivation between perovskites and NiOX is a challenge due to a hindered buried interface. In order to address this issue, self‐assembled monolayers (SAMs) are introduced as a buffer layer to prevent direct contact and non‐radiative recombination. While, the large dipole moment of SAMs increases the work function of NiOX, which is crucial for enhancing hole transport performance, given the low interfacial potential barrier for hole transfer. By a combination of the first‐principles calculations, drive‐level capacitance profiling, and transient absorption spectrum characterization, the understanding of the ion‐dipole interactions and interface passivation mechanism of potassium fluoride (KF) ultra‐thin buffer layer between SAMs and perovskites is provided. The efficiency of inverted PSCs as high as 23.25% is obtained, and the unencapsulated devices kept 90% of initial efficiency following 1400 h aging under nitrogen, which demonstrate remarkable long‐term stability as well. This novel strategy highlights the significance of SAMs dipole moment at the NiOX/perovskites interface and provides a new approach to address buried interfaces for high‐efficiency and long‐term stability in inverted PSCs. [ABSTRACT FROM AUTHOR]

Coating the perovskite layer via a two-step method is an adaptable solution for industries compared to the anti-solvent process. But what about the impact of unreacted PbI2? Usually, it is generated during perovskite conversion in a two-step method and considered beneficial within the grain boundaries, while also being accused of enhancing the interface defects and nonradiative recombination. Several additives are mixed in PbI2 precursors for the purpose of improving the perovskite crystallinity and hindering the Pb2+ defects. Herein, in lieu of adding additives to the PbI2, the effects of the PbI2 residue via the electron transport layer/perovskite interface modification are explored. Consequently, by introducing artemisinin decorated with hydrophobic alkyl units and a ketone group, it reduces the residual PbI2 and improves the perovskites' crystallinity by coordinating with Pb2+. In addition, artemisinin-deposited perovskite enhances both the stability and efficiency of perovskite solar cells by suppressing nonradiative recombination [ABSTRACT FROM AUTHOR]

A facilitated approach for improving the efficiency and stability of perovskite solar cells is explored by introducing the potassium cation-18-crown ether-6 (18C6) complexes at the interface of the electron transport layer and perovskite absorber layer. The results indicated that the 18C6 molecular can capture the potassium cation (K+) owing to the matched size of the K+ and crown ether cavity, which eventually suppresses the migration of K+ and then improving the stability of perovskite solar cells while retaining its excellent passivation effect. Furthermore, 18C6 also plays a crucial role in trap density reduction by mitigating the grain boundaries, passivating the uncoordinated Pb2+in the crystals, as witnessed by the SEM images, absorption spectra, carrier lifetime, and chemical bonding information. Ultimately, the short circuit current, open circuit voltage, fill factor, and conversion efficiency are enhanced accompanied with the improved long-term stability and eliminated hysteresis. The champion efficiency of 21.57% is delivered for the 18C6–K+ incorporated solar cells, much-leading the control cell without the 18C6–K+ incorporation with an efficiency of 20.25%. [Display omitted] • 18C6–K+ complexes are an effective approach for enhancing efficiency and stability. • K+ passivates the grain boundaries while 18C6 passivates the unsaturated cations. • The efficiency enhances from 20.25% up to 21.57% after 18C6–K+ incorporation. • The stability exhibits a significant improvement over 550 h of storage. [ABSTRACT FROM AUTHOR]

Passivating chemicals are recognized as an effective strategy to eliminate the defects inside and on the surface of the perovskite absorber. In this study, dithizone (DTZ) was explored as the passivation agent to modify the perovskite surface and improve the performance of the solar cells. DTZ contains the –NH, –SH, and benzene rings, where the –NH and –SH can interact with Pb2+ while the benzene can stabilize the perovskite. It is demonstrated that DTZ could effectively promote the quality of the perovskite films by reducing the excess lead iodide and defects on the surface, and eventually suppressing the non-radiative carrier recombination. Furthermore, the introduction of the DTZ interface can optimize the band alignment to facilitate the hole collection. Resultantly, device parameters, including current density, open-circuit voltage, fill factor, and the power conversion efficiency have been enhanced substantially from 16.96% to 19.67%. Meanwhile, the shelf stability also exhibited a considerable promotion. [Display omitted] • Dithizone is explored as an effective passivating chemicals for the perovskite surface. • The excess lead iodide and non-radiative carrier recombination are reduced after dithizone treatment. • The efficiency is enhanced from 16.96% up to 19.67%. [ABSTRACT FROM AUTHOR]