Mengjin Yang

Proton‐triggered degradation at the buried interface severely undermines the operational stability of inverted perovskite solar cells (PSCs). To address this issue, this work develops an ionization‐state‐directed sulfonate approach using sodium 2,2'‐disulfanediyldiethanesulfonate (DDANA). The pre‐deprotonated sulfonate terminals grant DDANA strong coordination with lead sites and drive its spontaneous aggregation at the perovskite and self‐assembled monolayer interface, forming robust multisite binding with the perovskite lattice. The enriched sulfonate groups build favorable interfacial dipoles to optimize energy level alignment and facilitate hole transport. The immobilized sulfonate groups act as conjugate‐based sites to competitively capture protons, while the disulfide skeleton enables reversible iodine‐redox to scavenge corrosive iodine species under operational stress. Dissociated sodium (Na ⁺ ) ions embed into lattice interstices and release residual tensile strain. As a result, DDANA‐modified inverted PSCs achieve a champion efficiency of 27.38% (certified 27.13%). The strategy extends seamlessly to flexible devices and rigid large‐area modules, delivering efficiencies of 25.88% and 23.33%, respectively. Moreover, the DDANA‐modified devices retain 98.9% of their initial efficiency after 1000 h of maximum power point tracking and 97.4% after cycling diurnals. This work establishes sulfonate ionization‐state engineering as a versatile molecular design platform for constructing chemically robust buried interfaces toward efficient, stable, and scalable perovskite photovoltaics.

Developing passivators that deliver multi‐mechanistic synergistic effects constitutes a highly efficacious strategy for crystallization regulation, while simultaneously serving as a critical approach to bolster the long‐term operational stability of perovskite solar cells. In this work, a series of amine‐derived functional additives was rationally engineered and systematically evaluated via molecular design strategy to precisely regulate both the substitution pattern and the chlorine atoms count. Notably, the dichloro‐substituted derivative 1‐(3,4‐dichlorophenyl)‐3‐(pyridin‐4‐yl)urea (DCLPU) demonstrates exceptional coordination passivation capability, an effect predominantly ascribed to the significantly enhanced electronegativity of its carbonyl group. This modification markedly reduces the perovskite crystallization rate and directs the preferential orientation of the perovskite (100) crystal facet. Furthermore, DCLPU suppresses non‑radiative recombination losses and weakens electron‑phonon coupling via energy level modulation. Consequently, the inverted device incorporating DCLPU attained a champion power conversion efficiency (PCE) of 27.32% (certified: 26.91%), alongside a corresponding module efficiency of 22.50%. These devices further exhibited outstanding thermal stability, ultraviolet resistance, and sustained operational durability. This work delineates a robust and practicable paradigm for advancing high‐efficiency, stable perovskite photovoltaic technologies.

Synergistic phosphine oxide coordination and CF ₃ -induced hydrophobicity suppress defects, phase segregation, and moisture ingress, enabling 23.67% 1.68 eV WBG perovskite cells and 28.9% flexible perovskite/CIGS tandems.

Commercializing flexible perovskite solar cells (f-PSCs) is hindered by poor interfacial contact and suboptimal crystallization, particularly in large-area perovskite solar modules (PSMs). Here, we propose an in situ stepwise polymerization strategy utilizing an epoxy-terminated monomer (BFDGE) and a curing agent (isophorone diamine, IPDA). A room-temperature pre-reaction enables precise tailoring of perovskite ink, ensuring reliable fabrication of perovskite films over large-area substrates. Subsequently, thermal annealing synchronizes the polymerization with perovskite crystallization, dynamically modulating the crystallization process. Consequently, rigid and flexible devices yield outstanding efficiencies of 27.16% (certified 26.87%) and 25.13%, respectively. The resultant cross-linked scaffold ensures superior durability, with devices retaining 93.3% of their initial efficiency following 1000 h of maximum power point (MPP) tracking and 96% after 630 h ultraviolet irradiation. Furthermore, minimodules (10.24 cm ² ) achieve high efficiencies of 23.25% (rigid) and 20.59% (flexible), with 95.1% retention after 200 thermal cycles (−40 to 85 °C). Notably, a submodule achieves an impressive efficiency of 22.60% (655.2 cm ² , certified 21.07%), establishing a new benchmark for large-area inverted PSMs.

The interaction between the hybrid component of self‐assembled monolayers (SAMs) and the perovskite precursor could delay the crystallization process, resulting in high‐quality perovskite film and highly efficient perovskite solar cells (PSCs). However, the intensity of interaction affects more precise control of crystallization speed. Herein, we introduce two pyridinium cation species to compare the intensity of their interaction with iodide. Our systematic investigation reveals that the more electron deficient 1‐methyl‐4‐(trifluoromethyl)pyridinium (CF ₃ Py ⁺ )‐based hybrid SAM enables a champion power conversion efficiency (PCE) of 27.07% (certified 26.8%) for a 0.06‐cm ² PSC, surpassing hybrid 1‐methylpyridinium (Py ⁺ )‐based device (26.42%) and pure 4PADCB‐based device (25.12%). The impressive PCE stems from fine‐tuning of crystallization speed through more intensive interaction between CF ₃ Py ⁺ and I ⁻ . Moreover, the stronger interaction inhibits iodide migration, which improves the light and thermal stability of the optimized PSCs. Our work demonstrates an effective approach to strengthening the interaction between pyridinium cations and iodide by incorporating an electron‐withdrawing group into the aromatic core, providing crucial insights into the manipulation of perovskite film crystallization.

The interaction between the hybrid component of self‐assembled monolayers (SAMs) and the perovskite precursor could delay the crystallization process, resulting in high‐quality perovskite film and highly efficient perovskite solar cells (PSCs). However, the intensity of interaction affects more precise control of crystallization speed. Herein, we introduce two pyridinium cation species to compare the intensity of their interaction with iodide. Our systematic investigation reveals that the more electron deficient 1‐methyl‐4‐(trifluoromethyl)pyridinium (CF ₃ Py ⁺ )‐based hybrid SAM enables a champion power conversion efficiency (PCE) of 27.07% (certified 26.8%) for a 0.06‐cm ² PSC, surpassing hybrid 1‐methylpyridinium (Py ⁺ )‐based device (26.42%) and pure 4PADCB‐based device (25.12%). The impressive PCE stems from fine‐tuning of crystallization speed through more intensive interaction between CF ₃ Py ⁺ and I ⁻ . Moreover, the stronger interaction inhibits iodide migration, which improves the light and thermal stability of the optimized PSCs. Our work demonstrates an effective approach to strengthening the interaction between pyridinium cations and iodide by incorporating an electron‐withdrawing group into the aromatic core, providing crucial insights into the manipulation of perovskite film crystallization.

Self‐assembled monolayers (SAMs) have become pivotal hole‐selective layers for efficient inverted perovskite solar cells (PSCs), yet conventional single‐component SAMs suffer from severe intermolecular aggregation, insufficient thermal anchoring, and weak crystallization templating, which severely limit efficiency and operational stability, especially in flexible configurations. Herein, we demonstrate a rationally designed molecular engineering approach for constructing robust buried bottom interfaces via multifunctional SAMs featuring bidentate phosphonic acid anchors, electron‐donating methoxy groups. Such elaborate molecular design enables strengthened interfacial binding, optimized energy‐level alignment, suppressed self‐aggregation, and oriented perovskite crystallization with relieved residual tensile strain. As a result, rigid PSCs achieve a champion efficiency of 27.15% (certified 26.51%), and flexible PSCs exhibit a remarkable efficiency of 25.37% with outstanding mechanical robustness. Moreover, the optimized devices deliver exceptional operational stability, retaining 97.5% of initial performance after 1000 h of continuous operation under ISOS‐L‐2 protocols. This work provides a universal molecular engineering paradigm toward high‐performance and ultra‐stable flexible perovskite photovoltaics via robust buried interface engineering.

Perovskite solar cells (PSCs) using self-assembled monolayers (SAMs) as hole transporting materials have achieved impressive efficiencies. However, the vulnerability of SAMs causes desorption under light and thermal stress. While various modifications to the conjugated core and anchoring group of SAMs have been explored, challenges in balancing efficiency and stability remain. Here, we introduce a new class of cross-linkable SAMs, uniquely functionalized at the molecular linker. Upon in situ cross-linking, these hybrid monolayers exhibit impressive conductivity and optimal energy level alignment, enabling a power conversion efficiency (PCE) of 26.76% (certified 26.45%) in PSCs. The perovskite solar cells with cross-linkable SAMs also demonstrate superior durability in ageing tests, retaining 99% of its initial PCE under more than 2000 hours thermal stress and 95% of that under 500 hours ultraviolet irradiation. Furthermore, the strategy has been applied in the fabrication of high-efficiency rigid and flexible mini-modules. This molecular design strategy offers a promising and versatile modification site for advancing SAMs-based interfaces in optoelectronic devices.

Self‐assembled molecules (SAMs) served as hole transport layers (HTLs) have dramatically contributed to the advancement of inverted perovskite solar cells (PSCs). However, further enhancement in the power conversion efficiency (PCE) and stability of these PSCs remains challenging due to issues such as inefficient charge transport, non‐uniform distribution of SAMs, and undesirable perovskite growing on SAM substrate. Herein, we demonstrate a stepwise brominating strategy to develop two efficient SAMs, namely (3‐(9‐bromo‐7H‐benzo[c]carbazol‐7‐yl)propyl)phosphonic acid (Br‐3PABCB) and 3‐(5,9‐dibromo‐7H‐benzo[c]carbazol‐7‐yl)propyl)phosphonic acid (2Br‐3PABCB), whose hole transport ability is enhanced by the increase in electron delocalization through C─H···Br interaction and the spatial arrangement is regulated via steric effect. Co‐assembly of Br‐3PABCB (co‐1Br) or 2Br‐3PABCB (co‐2Br) with (4‐(7H‐dibenzo[c,g]carbazol‐7‐yl)butyl)phosphonic acid (4PADCB) yields co‐self‐assembled monolayers (co‐SAMs), which achieve tight adsorption and uniform morphology on indium tin oxide (ITO), thereby regulating perovskite crystal growth and restraining interfacial nonradiative recombination losses. Consequently, the co‐1Br‐based device attains a notable PCE of 26.87% (certified 26.51%), while maintaining excellent thermal and operational stability. Moreover, co‐1Br is extended to fabricate perovskite solar module (PSM) with an aperture area of 13.9 cm ² , yielding an impressive PCE of 23.03%. This work provides valuable insights for designing favorable SAM contacts to advance the development of high‐performance PSCs.

An amphiphilic monomer for scalable flexible perovskite solar cells.