SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4491-3
Magnetic tunnel junctions (MTJs) with multiferroic tunneling barriers offer a pathway to fully electrically controlled multi-state memory, addressing the high energy costs and scalability limits of magnetically controlled counterparts. In this work, we propose a theoretical design achieving four or ten distinct resistance states via electrical control, with a giant tunneling magnetoresistance (TMR) ratio of 1.1×10^4% (11000%). This value surpasses all previously reported MTJs, including experimental systems such as CoFeB/MgO/CoFeB (TMR 65%, 4 states) and theoretical systems like Ga2O3/MgO/Ga2O3 (TMR 1120%, 2 states). The multiferroic barrier enables simultaneous control of ferroelectric and magnetic order parameters, allowing reversible switching between multiple resistance levels without external magnetic fields. Our first-principles calculations reveal that the high TMR arises from spin-dependent tunneling through the barrier, modulated by the ferroelectric polarization direction and magnetization configuration. The device operates with low write energy and exhibits non-volatile retention, making it suitable for high-density storage and in-memory computing. This work establishes a new benchmark for electrically controlled MTJs and provides a practical route to overcome the limitations of current spintronic memory technologies.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4381-5
Bismuth telluride (Bi2Te3)-based alloys remain the benchmark for low-temperature thermoelectric applications, yet their conversion efficiency is limited by the trade-off between electrical and thermal transport. This study introduces a pseudo grain boundary engineering strategy to simultaneously enhance the average figure of merit (ZT) in p-type (Bi,Sb)2Te3 (BST) materials. By incorporating Ag-based compounds, the carrier concentration is optimized via substitution of Ag+ ions, while the introduction of secondary phases at grain boundaries effectively suppresses lattice thermal conductivity. The approach yields a peak ZT of 1.35 at 393 K and an average ZT of 1.25 across 303–483 K, representing a significant improvement over pristine BST. Compared to prior reports, this work achieves superior average ZT while maintaining high electrical conductivity, addressing the longstanding bottleneck of thermal conductivity reduction without compromising carrier mobility. The findings underscore the efficacy of pseudo grain boundary engineering in advancing Bi2Te3-based thermoelectrics for solid-state cooling and power generation.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4106-8
Perovskite/organic tandem solar cells (PO-TSCs) have emerged as a compelling photovoltaic architecture to transcend the Shockley-Queisser limit of single-junction devices. By monolithically stacking a wide-bandgap (WBG) perovskite top cell and a narrow-bandgap (NBG) organic bottom cell, PO-TSCs enable broad spectral utilization and reduced thermalization loss, offering a viable pathway toward efficiencies beyond 30%. Their solution processability, compatibility with orthogonal solvents, and potential for lightweight, flexible, and semi-transparent modules further make them attractive for building integrated and portable electronics. However, the realization of high-performance PO-TSCs critically depends on precise carrier regulation across the entire multilayer stack, where inefficient charge transport, recombination losses, and interfacial bottlenecks often limit the overall power conversion efficiency (PCE) and stability. This review systematically examines the carrier-regulation strategies essential for advancing PO-TSCs, focusing on defect and phase-control in WBG perovskites, the design of optically transparent and electrically efficient interconnecting layers, and the enhancement of charge generation and collection in organic subcells. The integration of these approaches has recently enabled efficiencies exceeding 26%, demonstrating the rapid progress of the field. Ultimately, we conclude with an outlook on the remaining challenges in scalability, operational stability, and manufacturability, providing a roadmap for future research toward commercially viable tandem photovoltaics.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3714-3
Eco-friendly aqueous zinc batteries (AZBs) are promising alternatives to lead-acid batteries in applications requiring both safety and energy density. However, their practical deployment is hindered by the synergistic deterioration of zinc anodes—structural collapse and kinetic failure—under high depth of discharge (DOD) and high current densities, which severely limits actual energy and power densities. Here, we report a strategy for the in situ integration of a double-layer topological chitosan framework (D-CTS) on current collectors via regulating phase separation kinetics during multistage coordination-neutralization electrophoresis. The vertical through-hole array is formed by coupling instantaneous and delayed phase separation. Subsequently, a columnar zinc array is mediated by D-CTS to construct an integrated component (D-CTS-Zn) comprising a vertical through-hole separator and an array anode. The embedded interconnected nanonetworks within the through-hole walls enable dynamic equilibrium of the columnar zinc array through a lateral ion compensation mechanism. As a result, Zn||Zn symmetric cells with D-CTS-Zn stably cycle over 3000 cycles at 200 mA cm−2 under 60% DOD. The assembled D-CTS-Zn||MnO2 battery delivers an energy density of 83 Wh kg−1 at an ultrahigh power density of 9.25 kW kg−1. This work provides a constructive strategy for chitosan phase separation regulation and separator-induced reversible metal array anodes.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202509020
The AAOA-MBR (anaerobic-anoxic-oxic-anoxic membrane bioreactor) process is widely used in municipal wastewater treatment, but its multi-stage internal recirculation complicates sludge retention time (SRT) and carbon source distribution. This study systematically regulated three reflux ratios (R1: membrane tank to oxic tank; R2: oxic tank to anoxic I tank; R3: anoxic II tank to anaerobic tank) in a pilot-scale system (0.24 m3·d−1) to reveal their effects on nutrient removal and membrane fouling. When R1:R2:R3 = 300%:200%:100%, effluent COD, TN, TP, and NH3-N met discharge standards. Reducing R1 and R2, thereby decreasing total reflux ratio from R=6 to R=3, shortened SRT, which suppressed nitrifier accumulation and increased effluent COD and TN, but decreased TP. High-throughput sequencing of anoxic I and oxic tanks showed that denitrifying bacteria (Thauera and Ottowia) relative abundances decreased from 0.68% to 0.42% and 0.51% to 0.24%, respectively, while the phosphorus-accumulating organism Candidatus_Accumulibacter increased from 0.78% to 1.12%, enhancing phosphorus removal. Additionally, lowering R1 to 200% caused sludge accumulation in the membrane tank, exacerbating membrane fouling. Thus, internal recirculation ratios must be adjusted based on influent characteristics to balance nutrient removal and membrane performance.