Shifeng Zhao

The high‐performance energy storage ferroelectrics have drawn enormous attention, but one of the challenges for cutting‐edge applications is a limited operating temperature range. Guided by grain boundary structures, composition, and phase field simulation, the remarkable energy‐storage solid solutions were designed using ternary solid solutions 1.6SrTiO ₃ ·0.4(Bi _0.5 Na _0.5 )TiO ₃ ·Bi ₄ Ti ₃ O ₁₂ , where giant recoverable energy density U _re ∼ 85.0 J/cm ³ , ultrahigh efficiency ƞ ∼ 69.0% and the state‐of‐the‐art frequency stability were realized at Low Earth Orbit temperature range (−180°C–200°C). The emergent dipolar glass states induced by A‐site cationic disorder and size mismatch are the origin of thermal stability and performance retention of 94% at extreme temperatures, which is confirmed by the First Order Reversal Curves method, Arrott plot, and phase field simulation. This work highlights a route to achieve extreme‐temperature energy storage films.

The in-sensor computing paradigm, which enables rapid signal processing with low energy consumption, pursues a frontier model to reduce data transmission and redundancy. The direct conversion of light signals into photocurrent is achieved in multiferroic photodetectors, which implement in-sensor computing. The millisecond response and detectivity of ∼1015 Jones enable pronounced performance in wavelengths 300–430 nm. By leveraging the plastic photocurrent/photoconductance, Bi4Ti3−xFexO12 multiferroic photodetectors exhibit memory/forgetting and logic functions (OR, AND, and NOT) under light and electric pulse stimulation, which is attributed to the coupling of magnetic photocurrent with the imprinting effect. The observations highlight the advantages of in-sensor memory and computing.

Near-sensor computing technology shows high efficiency and intelligence, exhibiting significant promise in the post-Moore era. The light power density and wavelength are used as the stimulations to implement reconfigurable logic operations (AND, OR) in dual-band-response Bi _0.5 Na _0.5 Ti _0.85 Fe _0.15 O ₃ multiferroic photodetectors, where the polarization-dependent photocurrents are the weighting factors. The p-d hybridization between the O atom and Fe dopants constructs the mixed band structure and carrier transport network. The in-sensor computing photodetectors showcase optical encryption communication of the English alphabet and Chinese characters by ASCII code. This research holds promise for the in-sensor computing paradigm, enabling complex tasks.

Multimodal synapses with hybrid signal processing mechanisms are promising to enable complex functions of neural computing. However, the absent homology of physical mechanisms for bionic-coupled mapping behavior hinders multimodal synaptic application. Here, based on polarization dynamics, we explore a homeotic mechanism to achieve the multimodal mapping of emotion simulation and visual bionics in BaTiO3-based photo-ferroelectric synapses. Synaptic plasticity for multi-emotional evolution arises from weight-featured resistance switching in various ferroelectric memristors through the polarization-modulated interfacial barrier. Based on the regulation homology of polarization dynamics for the bulk photovoltaic effect, the optical synaptic responses of visual bionics are coupled into a precise emotion mapping with arousal-valence dimensions. These multimodal photo-ferroelectric synapses complete precise digit-pattern recognition within an artificial neural network system and possess rectifications against crosstalk and superior high thermal stability. Circuit simulations of optoelectronic mapping response display the application potential of multimodal synapses as smart decoupling components for balanced ternary computing. Our results provide a paradigm for designing multimodal devices with synergistic and coupled multi-synaptic functions.

Dielectric capacitors are vital components in advanced electronics and high-power electrical systems. A persistent challenge, however, is enhancing their energy density (Wrec) at low electric fields and voltages. Herein, we design a defect dipole engineered hybrid polar configuration to address this issue. By introducing defect dipoles in Na0.5Bi0.5Ti1–xAlxO3 (NBTA-x) films, tailored polar configurations comprising a ferroelectric domain matrix and sparse polar nanoregions are precisely engineered. The coexistence of macro- and micro-domains in the optimal proportion improves interdomain interactions, effectively suppressing hysteresis while still retaining ferroelectric polarization. Meanwhile, the depolarization field generated by defect dipoles drives the aligned domains to revert to their initial disordered state. Together, this dual mechanism weakens remanent polarization (Pr), enabling the simultaneous reduction of energy loss (Wloss) and enhancement of Wrec. Under a low electric field of 1756 kV cm−1, the NBTA-0.2 relaxor ferroelectric film delivers a high Wrec of 66.2 J cm−3 with an efficiency exceeding 70%. This work offers a generalizable strategy for developing high-performance dielectrics operating at low fields and voltages, benefiting from microscopic domain architecture and defect dipole design.

Optoelectronic logics are promising units of data encryption, which struggle with complex manufacture, owing to their fixed photodetection mode. Core-shell heterostructure Bi₆Ti₃Fe₂O₁₈@CuO ferroelectric photodetectors were fabricated by a one-pot method, which hosted UV detection and encrypted optical communication. The CuO quantum dot assembled homotypic transport shell was adopted in photodetectors, and the core-shell interfacial heterojunction as well as the ferroelectric core drove photocarrier separation. The Bi₆Ti₃Fe₂O₁₈@CuO (4 mg/mL) photodetectors show a self-powered performance of R ∼ 0.85 A/W, D* ∼ 4.9 × 10¹² Jones, and EQE ∼ 25.3%, which provide a simple strategy for encrypted communication. The dual-band (388 and 420 nm) photocurrent as a type of weight-factor, encrypted optical communication is realized based on "AND" optoelectronic logical operation, where the Chinese characters and capital letters "IMU" are showcased.

Efficient photocurrent generation in multiferroics Bi6Ti3CoxFe2−xO18 (x = 0.0–0.5) is achieved under the influence of an external magnetic field. By concurrently tracking changes in ferroelectric domain configurations and energy level splitting at room temperature, the underlying mechanisms responsible for the robust photocurrent and dual-band photoresponse (at 355 and 480 nm) are elucidated. In Bi6Ti3Co0.5Fe1.5O18, both the polarization-dependent open-circuit voltage and short-circuit current exhibit enhancements of threefold and fourfold, respectively, under a magnetic field of 1800 Oe. The observed quadratic dependence of photocurrent on magnetic field strength, along with a high magnetic responsivity (R = 72%), offers a promising framework for exploiting multiferroic coupling in next-generation photonic and optoelectronic devices.

Electric field control of magnetic properties in nanomaterials holds a significant prospect for high-density magnetic storage and sensors. Here, we demonstrate efficient electric field modulation of magnetic properties in nanocluster-assembled Ni0.74Co0.26/PMN-PT magnetoelectric heterostructures. Under the magnetic field of −44 Oe, electric field-induced tensile strain enhances the magnetization by 17.13% and shifts the coercive field by 10.3%. A key breakthrough resides in establishing the particle size dependence of electrical modulation. The critical size of 16.39 nm guarantees the optimal strain transfer under electric fields, where surface and bulk effects reach dynamic equilibrium. Furthermore, micromagnetic simulations firmly confirm that the magnetic property regulation by electric fields in nanocluster-assembled magnetoelectric heterostructures is via strain-mediated magnetic domain evolution. The sensitivity of the nanocluster size on the electrical control in cluster-assembled films advances the fundamental understanding and device applications for the converse magnetoelectric effect.

Coexistence of electric polarization with metallicity or superconductivity defines the exotic polar metallic or superconducting states, which are exceedingly rare due to inherent mutual exclusivity. Recently, interweaved charge-density-wave (CDW) and antipolar charge orders have been discovered in a metallic superatomic crystal Au ₆ Te ₁₂ Se ₈ (ATS). However, their interplay and competition with the emergent superconducting state remains elusive. Here, we report experimental investigations on the superconducting state, interacting with pre-existing CDW and antipolar metal in ATS crystals, using STM/STS. We clearly identify the distinct temperatures for Cooper pair preformation (9.9 K) and subsequent superconducting condensation (2.8 K). Our results reveal that the preformed Cooper pairs gradually suppress the existing CDW upon cooling. Moreover, the antipolar charge distribution is converted into a ferrielectric-like unipolar state by superconductivity below the superconducting transition. These findings establish ATS as a unique host for an exotic charge-polarized superconducting state, providing a promising platform for exploring novel polar-superconductivity interactions.