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Halide perovskite single crystals (SCs) have attracted much attention for their application in high-performance x-ray detectors owing to their desirable properties, including low defect density, high mobility–lifetime product (μτ), and long carrier diffusion length. However, suppressing the inherent defects in perovskites and overcoming the ion migration primarily caused by these defects remains a challenge. This study proposes a facile process for dipping Cs_0.05FA_0.9MA_0.05PbI₃ SCs synthesized by a solution-based inverse temperature crystallization method into a 2-phenylethylammonium iodide (PEAI) solution to reduce the number of defects, inhibit ion migration, and increase x-ray sensitivity. Compared to conventional spin coating, this simple dipping process forms a two-dimensional PEA₂PbI₄ layer on all SC surfaces without further treatment, effectively passivating all surfaces of the inherently defective SCs and minimizing ion migration. As a result, the PEAI-treated perovskite SC-based x-ray detector achieves a record x-ray sensitivity of 1.3 × 10⁵ μC Gy_air⁻¹ cm⁻² with a bias voltage of 30 V at realistic clinical dose rates of 1–5 mGy s⁻¹ (peak potential of 110 kVp), which is 6 times more sensitive than an untreated SC-based detector and 3 orders of magnitude more sensitive than a commercial α-Se-based detector. Furthermore, the PEAI-treated-perovskite SC-based x-ray detector exhibits a low detection limit (73 nGy s⁻¹), improved x-ray response, and clear x-ray images by a scanning method, highlighting the effectiveness of the PEAI dipping approach for fabricating next-generation x-ray detectors.

Halide perovskites with naturally coupled electron-ion dynamics hold great potential for nonvolatile memory applications. Self-rectifying memristors are promising as they can avoid sneak currents and simplify device configuration. Here we report a self-rectifying memristor firstly achieved in a single perovskite (NHCINH₃)₃PbI₅ (abbreviated as (IFA)₃PbI₅), which is sandwiched by Ag and ITO electrodes as the simplest cell in a crossbar array device configuration. The iodide ions of (IFA)₃PbI₅ can be easily activated, of which the migration in the bulk contributes to the resistance hysteresis and the reaction with Ag at the interface contributes to the spontaneous formation of AgI. The perfect combination of n-type AgI and p-type (IFA)₃PbI₅ gives rise to the rectification function like a p–n diode. Such a self-rectifying memristor exhibits the record-low set power consumption and voltage. This work emphasizes that the multifunction of ions in perovskites can simplify the fabrication procedure, decrease the programming power, and increase the integration density of future memory devices.

We use an automated research platform combined with machine learning to assess and understand the resilience against air and light during production of organic photovoltaic (OPV) devices from over 40 donor and acceptor combinations. The standardized protocol and high reproducibility of the platform results in a dataset of high variety and veracity to deploy machine learning models to encounter links between stability and chemical, energetic, and morphological structure. We find that the strongest predictor for air/light resilience during production is the effective gap E_g,eff which points to singlet oxygen rather than the superoxide anion being the dominant agent in degradation under processing conditions. A similarly good prediction of air/light resilience can also be achieved by considering only features from chemical structure, that is, information which is available prior to any experimentation.

Organic photovoltaics (OPVs) represent one of the most promising photovoltaic technologies owing to their high capacity to convert solar energy to electricity. With the continuous structure upgradation of photovoltaic materials, especially that of non-fullerene acceptors (NFAs), the OPV field has witnessed rapid progress with power conversion efficiency (PCE) exceeding 19%. However, it remains challenging to overcome the intrinsic trade-off between the photocurrent and photovoltage, restricting the further promotion of the OPV efficiency. In this regard, it is urgent to further tailor the structure of NFAs to broaden their absorption spectra while mitigating the energy loss of relevant devices concomitantly. Heteroatom substitution on the fused-ring π-core of NFAs is an efficient way to achieve this goal. In addition to improve the near-infrared light harvest by strengthening the intramolecular charge transfer, it can also enhance the molecular stacking via forming multiple noncovalent interactions, which is favorable for reducing the energetic disorder. Therefore, in this review we focus on the design rules of NFAs, including the polymerized NFAs, of which the core moiety is substituted by various kinds of heteroatoms. We also afford a comprehensive understanding on the structure–property−performance relationships of these NFAs. Finally, we anticipate the challenges restricting the efficiency promotion and industrial utilization of OPV, and provide potential solutions based on the further heteroatom optimization on NFA core-moiety.

Developing novel lead-free ferroelectric materials is crucial for next-generation microelectronic technologies that are energy efficient and environment friendly. However, materials discovery and property optimization are typically time-consuming due to the limited throughput of traditional synthesis methods. In this work, we use a high-throughput combinatorial synthesis approach to fabricate lead-free ferroelectric superlattices and solid solutions of (Ba_0.7Ca_0.3)TiO₃ (BCT) and Ba(Zr_0.2Ti_0.8)O₃ (BZT) phases with continuous variation of composition and layer thickness. High-resolution x-ray diffraction (XRD) and analytical scanning transmission electron microscopy (STEM) demonstrate high film quality and well-controlled compositional gradients. Ferroelectric and dielectric property measurements identify the “optimal property point” achieved at the composition of 48BZT–52BCT. Displacement vector maps reveal that ferroelectric domain sizes are tunable by varying {BCT–BZT}_N superlattice geometry. This high-throughput synthesis approach can be applied to many other material systems to expedite new materials discovery and properties optimization, allowing for the exploration of a large area of phase space within a single growth.

All-solid-state batteries equipped with solid-state electrolytes (SSEs) have gained significant interest due to their enhanced safety, energy density, and longevity in comparison to traditional liquid organic electrolyte-based batteries. However, many SSEs, such as sulfides and hydrides, are highly sensitive to water, limiting their practical use. As one class of important perovskites, the Ruddlesden–Popper perovskite oxides (RPPOs), show great promise as SSEs due to their exceptional stability, particularly in terms of water resistance. In this review, the crystal structure and synthesis methods of RPPOs SSEs are first introduced in brief. Subsequently, the mechanisms of ion transportation, including oxygen anions and lithium-ions, and the relevant strategies for enhancing their ionic conductivity are described in detail. Additionally, the progress made in developing flexible RPPOs SSEs, which are critical for flexible and wearable electronic devices, has also been summarized. Furthermore, the key challenges and prospects for exploring and developing RPPOs SSEs in all-solid-state batteries are suggested. This review presents in detail the synthesis methods, the ion transportation mechanism, and strategies to enhance the room temperature ionic conductivity of RPPOs SSEs, providing valuable insights on enhancing their ionic conductivity and thus for their practical application in solid-state batteries.

The highly ordered film assembled by regularly 1D nanostructures has potential prospects in electronic, photoelectronic and other fields because of its excellent light-trapping effect and electronic transport property. However, the controlled growth of highly ordered film remains a great challenge. Herein, large-area and highly ordered Bi₂S₃ film is synthesized on fluorophlogopite mica substrate by chemical vapor deposition method. The Bi₂S₃ film features hollowed-out crosslinked network structure, assembled by 1D nanobelts that regularly distribute in three orientations, which agrees well with the first principles calculations. Based on the as-grown Bi₂S₃ film, the broadband photodetector with a response range from 365 to 940 nm is fabricated, exhibiting a maximum responsivity up to 98.51 mA W^–1, specific detectivity of 2.03 × 10¹⁰ Jones and fast response time of 35.19 ms. The stable instantaneous on/off behavior for 500 cycles and reliable photoresponse characteristics of the Bi₂S₃ photodetector after storage in air for 6 months confirm its excellent long-term stability and air stability. Significantly, as sensing pixel and signal receiving terminal, the device successfully achieves high-resolution imaging of characters of “H”, “I” and “T”, and secure transmission of confidential information. This work shows a great potential of the large-area and highly ordered Bi₂S₃ film toward the development of future multiple functional photoelectronic applications.

Flexible electronics has emerged as a continuously growing field of study. Two-dimensional (2D) materials often act as conductors and electrodes in electronic devices, holding significant promise in the design of high-performance, flexible electronics. Numerous studies have focused on harnessing the potential of these materials for the development of such devices. However, to date, the incorporation of 2D materials in flexible electronics has rarely been summarized or reviewed. Consequently, there is an urgent need to develop comprehensive reviews for rapid updates on this evolving landscape. This review covers progress in complex material architectures based on 2D materials, including interfaces, heterostructures, and 2D/polymer composites. Additionally, it explores flexible and wearable energy storage and conversion, display and touch technologies, and biomedical applications, together with integrated design solutions. Although the pursuit of high-performance and high-sensitivity instruments remains a primary objective, the integrated design of flexible electronics with 2D materials also warrants consideration. By combining multiple functionalities into a singular device, augmented by machine learning and algorithms, we can potentially surpass the performance of existing wearable technologies. Finally, we briefly discuss the future trajectory of this burgeoning field. This review discusses the recent advancements in flexible sensors made from 2D materials and their applications in integrated architecture and device design.

The potential of three-dimensional (3D) printing technology in the fabrication of advanced polymer composites is becoming increasingly evident. This review discusses the latest research developments and applications of 3D printing in polymer composites. First, it focuses on the optimization of 3D printing technology, that is, by upgrading the equipment or components or adjusting the printing parameters, to make them more adaptable to the processing characteristics of polymer composites and to improve the comprehensive performance of the products. Second, it focuses on the 3D printable novel consumables for polymer composites, which mainly include the new printing filaments, printing inks, photosensitive resins, and printing powders, introducing the unique properties of the new consumables and different ways to apply them to 3D printing. Finally, the applications of 3D printing technology in the preparation of functional polymer composites (such as thermal conductivity, electromagnetic interference shielding, biomedicine, self-healing, and environmental responsiveness) are explored, with a focus on the distribution of the functional fillers and the influence of the topological shapes on the properties and functional characteristics of the 3D printed products. The aim of this review is to deepen the understanding of the convergence between 3D printing technology and polymer composites and to anticipate future trends and applications.

Soft molecule-based ferroelectrics with unique structural flexibility hold a promise for versatile applications of non-volatile memory, imaging and photovoltaic devices. Except for few polymers (e.g., polyvinylidene fluoride, PVDF), it is challenging to exploit soft ferroelectric crystals toward free-standing flexible photoactive devices. We here report a multiaxial soft molecule-based ferroelectric, (n-PA)₂PbCl₄ (1, where n-PA⁺ is n-pentylammonium), of which spontaneous polarization can be reversibly switched in both crystal and powder forms. Strikingly, single crystals of 1 have unusual structural flexibility and bendability, achieving the self-standing bending with a bending radius of ~0.22 mm. Besides, the pyroelectric activities are also preserved for these single crystals after several bending cycles. Further, the bendable crystal-based photodetector of 1 allows broadband photoactivities via the photo-pyroelectric effect, covering a wide range from 405 to 940 nm spectral region, breaking through the limit of optical absorption bandgap. As the first study of bendable free-standing photo-pyroelectric detectors in ferroelectric crystals, our work sheds light on the assembly of flexible smart photoelectric devices.