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The interface between the perovskite layer and electron transporting layer is a critical determinate for the performance and stability of perovskite solar cells (PSCs). The heterogeneity of the interface critically affects the carrier dynamics at the buried interface. To address this, a bridging molecule, (2-aminoethyl)phosphonic acid (AEP), is introduced for the modification of SnO 2 /perovskite buried interface in n-i-p structure PSCs. The phosphonic acid group strongly bonds to the SnO 2 surface, effectively suppressing the surface carrier traps and leakage current, and uniforming the surface potential. Meanwhile, the amino group influences the growth of perovskite film, resulting in higher crystallinity, phase purity, and fewer defects. Furthermore, the bridging molecules facilitate the charge extraction at the interface, as indicated by the femtosecond transient reflection (fs-TR) spectroscopy, leading to champion power conversion efficiency (PCE) of 26.40% (certified 25.98%) for PSCs. Additionally, the strengthened interface enables improved operational durability of ≈1400 h for the unencapsulated PSCs under ISOS-L-1I protocol., (© 2024 Wiley‐VCH GmbH.)

Organic-inorganic hybrid perovskites have emerged as highly promising candidates for photovoltaic applications, owing to the exceptional optoelectronic properties and low cost. Nonetheless, the performance and stability of solar cells suffer from the defect states of perovskite films aroused by non-optically active phases and non-centralized crystal orientation. Herein, a versatile organic molecule, Hydantoin, to modulate the crystallization of perovskite, is developed. Benefiting from the diverse functional groups, more spatially oriented perovskite films with high crystallinity are formed. This enhancement is accompanied by a conspicuous reduction in defect density, yielding efficiency of 25.66% (certified 25.15%), with superb environmental stability. Notably, under the standard measurement conditions (ISOS-L-1I), the maximum power point (MPP) output maintains 96.8% of the initial efficiency for 1600 h and exhibits excellent ion migration suppression. The synergistic regulation of crystallization and spatial orientation offers novel avenues for propelling perovskite solar cell (PSC) development., (© 2024 Wiley‐VCH GmbH.)

Polycrystalline perovskite films fabricated on flexible and textured substrates often are highly defective, leading to poor performance of perovskite devices. Finding substrate-tolerant perovskite fabrication strategies is therefore paramount. Herein, this study shows that adding a small amount of Cadmium Acetate (CdAc 2 ) in the PbI 2 precursor solution results in nano-hole array films and improves the diffusion of organic salts in PbI 2 and promotes favorable crystal orientation and suppresses non-radiative recombination. Polycrystalline perovskite films on the flexible substrate with ultra-long carrier lifetimes exceeding 6 µs are achieved. Eventually, a power conversion efficiency (PCE) of 22.78% is obtained for single-junction flexible perovskite solar cells (FPSCs). Furthermore, it is found that the strategy is also applicable for textured tandem solar cells. A champion PCE of 29.25% (0.5003 cm 2 ) is demonstrated for perovskite/silicon tandem solar cells (TSCs) with CdAc 2 . Moreover, the un-encapsulated TSCs maintains 109.78% of its initial efficiency after 300 h operational at 45 °C in a  nitrogen atmosphere. This study provides a facile strategy for achieving high-efficiency perovskite-based solar cells., (© 2023 Wiley-VCH GmbH.)

Nickel oxide (NiO x ) is an attractive hole-transport material for efficient and stable p-i-n metal-halide perovskite solar cells (PSCs). However, an undesirable redox reaction occurs at the NiO x /perovskite interface, which results in a low open-circuit voltage (V OC ), instability, and phase separation of the NiO x -based wide-bandgap perovskite (Br > 20%). In order to simultaneously address the abovementioned phase separation problem and redox chemistry at the perovskite/NiO x interface, the bandgap is widened from 1.64 to 1.67 eV by adding inorganic CsPbCl 3 -clusters (3 mol%) to the Cs 22 Br 15 perovskite precursor solution. Moreover, adding extra 2 mol% CsCl enriches the NiO x /perovskite interface with Cl, thereby preventing the redox reaction at the interface, while controlling the Br content to within 15% improves the photostability of the wide-bandgap perovskite. Consequently, the power conversion efficiency (PCE) of a single-junction p-i-n PSC increases from 17.82% to 19.76%, which leads to the fabrication of highly efficient monolithic p-i-n-type NiO x -based perovskite/silicon tandem solar cells with PCEs of up to 27.26% (certified PCE: 27.15%). The perovskite to an n-i-p-type perovskite/silicon tandem solar cell is also applied to deliver a V OC of 1.93 V and a final efficiency of 25.5%. These findings provide critical insight into the fabrication of highly efficient and stable wide-bandgap perovskites., (© 2022 Wiley-VCH GmbH.)