Chaohui Li

High efficiency inverted perovskite solar cells often rely on nickel‐containing hole‐selective interfaces such as NiOx. However, the use of nickel presents sustainability challenges, as the material is inherently toxic and cross‐contamination during end‐of‐life processing can compromise material recovery and recyclability. Here, we develop a nickel‐free hole‐selective interface material based on phenyl‐substituted phosphonic‐acid carbazole self‐assembled monolayers (Ph‐nPACz). Candidate molecules were identified through rational structure‐property screening of the substituents of the carbazole core, anchoring groups and linkers. Among this molecular family, Ph‐5PACz delivers the best overall performance, offering improved interfacial wettability and enhanced buried‐interface stability compared to the NiOx/Me‐4PACz reference. Devices incorporating Ph‐5PACz achieve a power conversion efficiency of 25.3%, compared to 21.7% for the control, driven by a higher fill factor and efficient charge extraction. The chemical robustness of the nickel‐free interface enables a closed‐loop recycling route unavailable to nickel‐based devices, with recycled‐ITO devices retaining close to 98% of their initial performance. Coupled life‐cycle and techno‐economic analyses further indicate substantial sustainability gains, including reduced energy demand, markedly lower raw metal usage and toxicity‐related impacts, and a generalized reduction of up to 29% across ReCiPe endpoint indicators.

Flexible lead‐halide perovskite solar modules with carbon electrodes (C‐fPSMs) are promising for printed photovoltaics due to their low cost and compatibility with roll‐to‐roll (R2R) fabrication. However, the mechanical fragility of microcrystalline perovskite films, arising from their high grain‐boundary density, limits their practical application. Here, we report a vapor‐phase grain‐boundary anchoring strategy via thiol vapor annealing to molecularly toughen printed perovskite layers. Thiol molecules interact with intermediate species and preferentially anchor at surfaces and grain boundaries, reprogramming crystallization across the film. This chemomechanical conditioning promotes grain growth, reduces trap density, and transforms the deformation behavior from brittle fracture to ductile strain accommodation, as evidenced by reduced Young's modulus, increased yield strain, and significantly enhanced fracture toughness. As a result, treated devices retain 93% of their initial performance after 25 000 bending cycles, representing a new benchmark for flexible perovskite cells. In addition, improved film uniformity and interfacial contact enable power conversion efficiencies of 15.7% for R2R‐printed cells and 12.1% for modules (20.25 cm ² ), with scalability demonstrated up to 900 cm ² (17.26%). This work provides a scalable strategy to simultaneously enhance mechanical robustness and photovoltaic performance.

Flexible lead‐halide perovskite solar modules with carbon electrodes (C‐fPSMs) are promising for printed photovoltaics due to their low cost and compatibility with roll‐to‐roll (R2R) fabrication. However, the mechanical fragility of microcrystalline perovskite films, arising from their high grain‐boundary density, limits their practical application. Here, we report a vapor‐phase grain‐boundary anchoring strategy via thiol vapor annealing to molecularly toughen printed perovskite layers. Thiol molecules interact with intermediate species and preferentially anchor at surfaces and grain boundaries, reprogramming crystallization across the film. This chemomechanical conditioning promotes grain growth, reduces trap density, and transforms the deformation behavior from brittle fracture to ductile strain accommodation, as evidenced by reduced Young's modulus, increased yield strain, and significantly enhanced fracture toughness. As a result, treated devices retain 93% of their initial performance after 25 000 bending cycles, representing a new benchmark for flexible perovskite cells. In addition, improved film uniformity and interfacial contact enable power conversion efficiencies of 15.7% for R2R‐printed cells and 12.1% for modules (20.25 cm ² ), with scalability demonstrated up to 900 cm ² (17.26%). This work provides a scalable strategy to simultaneously enhance mechanical robustness and photovoltaic performance.

Perovskite solar cells (PSCs) experience significant photovoltage losses due to nonradiative recombination, especially in p–i–n devices with Fullerene C ₆₀ as the electron transport layer (ETL), which limits device performance. To tackle this issue, we propose a strategy that synergistically suppresses nonradiative recombination at the perovskite/C ₆₀ interface by employing a 2D heterointerface with a two‐site anchor bridge, which reduces the surface defect density. This process elevates the fermi level and enhances the electric field, facilitating electron extraction at the perovskite/C ₆₀ heterointerface. As a result, nonradiative recombination at this electron‐selective perovskite contact is greatly suppressed. p–i–n PSCs fabricated using this interface engineering approach achieved a power conversion efficiency (PCE) of 26.32% and demonstrated excellent stability under continuous maximum power point tracking, along with an open‐circuit voltage (Voc) of 1.217 V. This broadly applicable and scalable approach further delivers an impressive V oc of up to 1.368 V in wide‐bandgap (1.8 eV) devices. Overall, the strategy offers a viable pathway toward efficient and stable inverted PSCs, demonstrating broad compatibility with diverse perovskite compositions.

Interfacial instability of n ‐type contacts remains a key barrier to the commercialization of perovskite solar cells (PSCs), as coupled lattice stress and ion migration rapidly deteriorate electronic order and structural integrity. Here, we report a fully solution‐processed n ‐type interfacial architecture that unifies mechanical compliance, electronic stabilization, and thickness‐insensitive operation. A thermally in situ self‐crosslinked bathocuproine derivative (c‐BCP) is integrated with a π‐conjugated n ‐type conductive ink (PBFDO:PEOx) to form a mechanically continuous yet electronically selective junction that remains effective across thicknesses approaching 60 nm. This composite interlayer effectively redistributes interfacial stress, suppresses halide migration, and minimizes defect‐assisted nonradiative recombination. By coupling elastic energy dissipation with directional charge transport, the design resolves the long‐standing trade‐off between interfacial robustness and carrier extraction in n ‐type contacts. Devices incorporating this interlayer deliver a champion efficiency of 26.37% and retain >92% of their initial performance after 1000 h of continuous illumination under thermal stress. These results establish a generalizable and manufacturing‐ready framework for thick, solution‐processable n ‐type contacts, enabling intrinsically durable and high‐efficiency perovskite optoelectronics.

Monolithic perovskite–organic tandem solar cells (P–O TSCs) establish a mutual protection system, which enables high-efficiency P–O TSCs (25.12%) to achieve exceptional operational stability, retaining over 91% after 1000-hour illumination.

Ordered one dimensional perovskite single-crystal nanowire arrays, which combine high surface-to-volume ratios, directional charge transport, and mechanical flexibility, are typically prepared through solution or vapor phase techniques using templates of silicon, polydimethylsiloxane, photoresist, or aluminum oxide to control crystal growth. However, the size limits of these templates restrict the scalability of the arrays. Here, we introduce a dynamic template-assisted coating strategy that integrates blade coating to address this limitation. The method enables deposition of nanowire arrays on substrates with an area 12 times larger than the template. Incorporating a fluorinated passivating agent into the precursor suppresses surface defect formation and improves structural quality. Photodetectors based on MAPbBr ₃ arrays achieve a detectivity of 3.9 × 10 ¹⁴ Jones, a linear dynamic range of 160.3 dB, and a responsivity of 1660 A W ^-1 , and retain 90.3% of their photocurrent after 300 h at 85% relative humidity without encapsulation.

Perovskite memristors have emerged as promising candidates for neuromorphic computing due to their simple fabrication process and mixed ionic and electronic properties. Among them, all-inorganic CsPbBr₃ perovskites have garnered significant interest due to their excellent stability. However, the low solubility of cesium bromide (CsBr) in most common solvents poses a major challenge in fabricating high-quality, pinhole-free CsPbBr₃ films for memory device applications using a convenient one-step solution method. In this work, a facile one-step spin-coating approach was employed to fabricate CsPbBr₃-based memristors, incorporating a carbohydrazide (CBH) additive into the perovskite precursor to enhance device performance. The modified device exhibited an improved ON/OFF ratio, enhanced endurance, and longer retention time. Furthermore, it successfully emulated key synaptic functions, including excitatory postsynaptic current, paired-pulse facilitation, long-term potentiation/depression, and learning-forgetting-relearning behaviors, effectively mimicking biological synapses. Additionally, an associative learning experiment inspired by Pavlov's dog experiment was conducted, demonstrating memory formation and extinction under optical and electrical stimuli. The fabricated perovskite memristor was further evaluated in a convolutional neural network for Fashion MNIST classification, achieving a high recognition accuracy of 89.07%, confirming its potential for neuromorphic computing applications. This study highlights the effectiveness of additive engineering as a strategy for developing high-performance perovskite-based neuromorphic electronics.

Achieving high performance and long-term stability in perovskite solar cells (PSCs) typically requires the use of surface passivation layers to suppress the interfacial defects. However, these additional passivation agents often introduce chemical and structural instabilities, limiting the device lifetime. Here, we present a molecular engineering strategy utilizing a chiral series of C₆₀-Furan-Sugar (CFS) fullerene derivatives blended with [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM) to modify the electron transport layer (ETL). The incorporation of CFSs significantly enhances the electron mobility and dielectric constant of the ETL, while their intrinsic passivation functionality effectively passivates perovskite surface defects. As a result, PSCs employing PCBM:CFS-RS blends achieve a power conversion efficiency (PCE) of 25.81% without the use of additional passivation layers and retain 95% of their initial performance after 1000 h of aging. Notably, CFS-RS is a chiral molecule bearing a side chain with R/S configurational isomers, which facilitates interfacial compatibility and contributes to the enhanced device performance. This work demonstrates that tuning the orientation of polar substituents in fullerene side chains can effectively influence the optoelectronic properties of the blended films, thereby simultaneously enhancing both efficiency and stability in PSCs.

Ligand engineering is an effective method to reduce defects in perovskite solar cells (PSCs) and to enhance efficiency.