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Liquid metal (LM) droplets show the superiority in coalescing into integral liquid conductors applicable in flexible and deformable electronics. However, the large surface tension, oxide shells and poor compatibility with most other materials may prevent spontaneous coalescence of LM droplets and/or hybridisation into composites, unless external interventions (e.g., shear and laser) are applied. Here, we show that biological nanofibrils (NFs; including cellulose, silk fibroin and amyloid) enable evaporation-induced sintering of LM droplets under ambient conditions into conductive coating on diverse substrates and free-standing films. The resultants possess an insulating NFs-rich layer and a conductive LM-rich layer, offering flexibility, high reflectivity, stretchable conductivity, electromagnetic shielding, degradability and rapid actuating behaviours. Thus this sintering approach not only extends fundamental knowledge about sintering LM droplets, but also starts a new scenario of producing flexible coating and free-standing composites with flexibility, conductivity, sustainability and degradability, and applicable in microcircuits, wearable electronics and soft robotics. Providing mechanical sintering of liquid metal droplets under ambient conditions for flexible electronics remains elusive. Here, they propose biological nanofibrils for enabling evaporation-induced sintering of EGaIn droplets into conductive coating on diverse substrates and free-standing films.

This paper uses the data of Chinese cities and A-share listed companies from 2010 to 2022 and utilizes the implementation of Broadband China as a quasi-natural experiment to assess the impact of digital infrastructure construction, as exemplified by Broadband China, on enterprise carbon emissions. By applying the difference-in-differences method, the findings indicate that developing digital infrastructure can help reduce carbon emissions in enterprises. This reduction is achieved primarily by improving the efficiency of energy utilization in urban areas and enhancing corporate green technological innovation. Additionally, the impact of digital infrastructure on lowering carbon emissions varies by corporation and region.

Metal halide perovskites (MHPs), emerging as innovative and promising semiconductor materials with prominent optoelectronic properties, has been pioneering a new era of light management (ranging from emission, absorption, modulation, to transmission) for next-generation optoelectronic technology. Notably, the exploration of fundamental characteristics of MHPs and their devices is the main research theme during the past decade, while in the next decade, it will be primarily critical to promote their implantation in the next-generation optoelectronics. In this review, we first retrospect the historical research milestones of MHPs and their optoelectronic devices. Thereafter, we introduce the origin of the unique optoelectronic features of MHPs, based on which we highlight the tunability of these features via regulating the phase, dimensionality, composition, and geometry of MHPs. Then, we show that owing to the convenient property control of MHPs, various optoelectronic devices with target performance can be designed. At last, we emphasize on the revolutionary applications of MHPs-based devices on the existing optoelectronic systems. This review demonstrates the key role of MHPs played in the development of modern optoelectronics, which is expected to inspire the novel research directions of MHPs and promote the widespread applications of MHPs in the next-generation optoelectronics.

Medical reports have significant clinical value to radiologists and specialists, especially during a pandemic like COVID. However, beyond the common difficulties faced in the natural image captioning, medical report generation specifically requires the model to describe a medical image with a fine-grained and semantic-coherence paragraph that should satisfy both medical commonsense and logic. Previous works generally extract the global image features and attempt to generate a paragraph that is similar to referenced reports; however, this approach has two limitations. Firstly, the regions of primary interest to radiologists are usually located in a small area of the global image, meaning that the remainder parts of the image could be considered as irrelevant noise in the training procedure. Secondly, there are many similar sentences used in each medical report to describe the normal regions of the image, which causes serious data bias. This deviation is likely to teach models to generate these inessential sentences on a regular basis. To address these problems, we propose an Auxiliary Signal-Guided Knowledge Encoder-Decoder (ASGK) to mimic radiologists’ working patterns. Specifically, the auxiliary patches are explored to expand the widely used visual patch features before fed to the Transformer encoder, while the external linguistic signals help the decoder better master prior knowledge during the pre-training process. Our approach performs well on common benchmarks, including CX-CHR, IU X-Ray, and COVID-19 CT Report dataset (COV-CTR), demonstrating combining auxiliary signals with transformer architecture can bring a significant improvement in terms of medical report generation. The experimental results confirm that auxiliary signals driven Transformer-based models are with solid capabilities to outperform previous approaches on both medical terminology classification and paragraph generation metrics.

Circularly polarized light (CPL) adds a unique dimension to optical information processing and communication. Integrating CPL sensitivity with light learning and memory in a photonic artificial synapse (PAS) device holds significant value for advanced neuromorphic vision systems. However, the development of such systems has been impeded by the scarcity of suitable CPL active optoelectronic materials. In this work, we employ a helical chiral perovskite hybrid combined with single-wall carbon nanotubes to achieve circularly polarized ultraviolet neuromorphic vision sensing and imaging. The heterostructure demonstrates long-term charge storage as evidenced by multiple-pulsed transient absorption measurements and highly sensitive circular polarization-dependent photodetection, thereby enabling efficient CPL-resolved synaptic and neuromorphic behaviors. Significantly, our PAS sensor arrays adeptly visualize, discriminate, and memorize distinct circularly polarized images with up to 93% recognition accuracy in spiking neural network simulations. These findings underscore the pivotal role of chiral perovskites in advancing PAS technology and circular polarization-enhanced ultraviolet neuromorphic vision systems. Circularly polarized light adds a unique dimension to optical information processing and communication. Here, the authors present a development of a photonic artificial synapse device using chiral perovskite hybrid materials and carbon nanotubes. The heterostructure exhibits efficient synaptic and neuromorphic behaviors, enabling accurate recognition of circularly polarized images.

The slow bimolecular recombination that drives three-dimensional lead-halide perovskites’ outstanding photovoltaic performance is conversely a fundamental limitation for electroluminescence. Under electroluminescence working conditions with typical charge densities lower than 10 15  cm −3 , defect-states trapping in three-dimensional perovskites competes effectively with the bimolecular radiative recombination. Herein, we overcome this limitation using van-der-Waals-coupled Ruddlesden-Popper perovskite multi-quantum-wells. Injected charge carriers are rapidly localized from adjacent thin few layer ( n ≤4) multi-quantum-wells to the thick ( n ≥5) multi-quantum-wells with extremely high efficiency (over 85%) through quantum coupling. Light emission originates from excitonic recombination in the thick multi-quantum-wells at much higher decay rate and efficiency than bimolecular recombination in three-dimensional perovskites. These multi-quantum-wells retain the simple solution processability and high charge carrier mobility of two-dimensional lead-halide perovskites. Importantly, these Ruddlesden-Popper perovskites offer new functionalities unavailable in single phase constituents, permitting the transcendence of the slow bimolecular recombination bottleneck in lead-halide perovskites for efficient electroluminescence. Slow bimolecular recombination in three-dimensional halide perovskites represents a fundamental limitation for electroluminescence efficiency. Using time-resolved spectroscopy Xing et al . demonstrate that this limitation can be overcome by employing van-der-Waals-coupled multiple quantum well structures.

All-small-molecule organic solar cells with good batch-to-batch reproducibility combined with non-halogen solvent processing show great potential for commercialization. However, non-halogen solvent processing of all-small-molecule organic solar cells are rarely reported and its power conversion efficiencies are very difficult to improve. Herein, we designed and synthesized a small molecule donor BM-ClEH that can take advantage of strong aggregation property induced by intramolecular chlorine-sulfur non-covalent interaction to improve molecular pre-aggregation in tetrahydrofuran and corresponding micromorphology after film formation. Tetrahydrofuran-fabricated all-small-molecule organic solar cells based on BM-ClEH:BO-4Cl achieved high power conversion efficiencies of 15.0% in binary device and 16.1% in ternary device under thermal annealing treatment. In contrast, weakly aggregated BM-HEH without chlorine-sulfur non-covalent bond is almost inefficient under same processing conditions due to poor pre-aggregation induced disordered π-π stacking, indistinct phase separation and exciton dissociation. This work promotes the development of non-halogen solvent processing of all-small-molecule organic solar cells and provides further guidance. The development of non-halogen solvent processed all-small-molecule organic solar cells was challenging. Here, the authors employ a small molecule donor with strong aggregation property to improve molecular pre-aggregation in tetrahydrofuran, realizing ternary device with efficiency of 16.1%.

Hot-carrier solar cells can overcome the Shockley-Queisser limit by harvesting excess energy from hot carriers. Inorganic semiconductor nanocrystals are considered prime candidates. However, hot-carrier harvesting is compromised by competitive relaxation pathways (for example, intraband Auger process and defects) that overwhelm their phonon bottlenecks. Here we show colloidal halide perovskite nanocrystals transcend these limitations and exhibit around two orders slower hot-carrier cooling times and around four times larger hot-carrier temperatures than their bulk-film counterparts. Under low pump excitation, hot-carrier cooling mediated by a phonon bottleneck is surprisingly slower in smaller nanocrystals (contrasting with conventional nanocrystals). At high pump fluence, Auger heating dominates hot-carrier cooling, which is slower in larger nanocrystals (hitherto unobserved in conventional nanocrystals). Importantly, we demonstrate efficient room temperature hot-electrons extraction (up to ∼83%) by an energy-selective electron acceptor layer within 1 ps from surface-treated perovskite NCs thin films. These insights enable fresh approaches for extremely thin absorber and concentrator-type hot-carrier solar cells. Harvesting excess energy from above-band gap photons could lead to solar cells which exceed conventional efficiency limits. Li et al ., study hot carrier cooling in hybrid perovskite materials with reduced dimensionality using transient absorption spectroscopy and demonstrate efficient hot-electron extraction in such systems.

Memory transistors based on two-dimensional (2D) ferroelectric semiconductors are intriguing for next-generation in-memory computing. To date, several 2D ferroelectric materials have been unveiled, among which 2D In 2 Se 3 is the most promising, as all the paraelectric (β), ferroelectric (α) and antiferroelectric (β′) phases are found in 2D quintuple layers. However, the large-scale synthesis of 2D In 2 Se 3 films with the desired phase is still absent, and the stability for each phase remains obscure. Here we show the successful growth of centimetre-scale 2D β-In 2 Se 3 film by chemical vapour deposition including distinct centimetre-scale 2D β′-In 2 Se 3 film by an InSe precursor. We also demonstrate that as-grown 2D β′-In 2 Se 3 films on mica substrates can be delaminated or transferred onto flexible or uneven substrates, yielding α-In 2 Se 3 films through a complete phase transition. Thus, a full spectrum of paraelectric, ferroelectric and antiferroelectric 2D films can be readily obtained by means of the correlated polymorphism in 2D In 2 Se 3 , enabling 2D memory transistors with high electron mobility, and polarizable β′–α In 2 Se 3 heterophase junctions with improved non-volatile memory performance. A chemical-vapour-deposition-based approach enables the phase-controllable synthesis of large-scale two-dimensional β-, β′- and α-In 2 Se 3 films.