SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4279-0
Inkjet printing has emerged as a viable additive manufacturing route for organic light-emitting diodes (OLEDs), offering drop-on-demand patterning, high material utilization, and compatibility with large-area flexible substrates. This review critically examines the formulation science, printhead physics, and drying kinetics that govern the quality of inkjet-printed organic layers. We analyze the rheological window required for stable jetting, typically 1–20 mPa·s viscosity and 25–45 mN/m surface tension, and the dimensionless Ohnesorge number (0.1 < Z < 1) that defines satellite-free droplet formation. The coffee-ring effect, driven by capillary flow and solvent evaporation gradients, remains the dominant failure mode for pixel non-uniformity; binary solvent systems and substrate temperature control (40–60 °C) mitigate this. We survey recent progress in printed hole-transport, emissive, and electron-transport layers, with particular attention to cross-linkable hole-transport materials that resist interlayer dissolution. Device performance metrics from printed OLEDs now reach external quantum efficiencies of 15–20% for fluorescent emitters and >25% for phosphorescent systems, with operating lifetimes (T95) exceeding 1,000 hours at 1,000 cd/m². We identify remaining bottlenecks: nozzle clogging from aggregated nanoparticles, film thickness variation across large panels, and the absence of standardized ink formulations. The review concludes with a roadmap for industrial adoption, emphasizing in-line metrology and closed-loop process control as prerequisites for yield parity with vacuum-deposited OLEDs.
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/s40843-026-4287-1
Atomic-level manufacturing is a frontier technology enabling materials to achieve ultimate performance. This study explores the potential applications and critical scientific issues of metal atomic clusters, which are predominantly used in catalysis but suffer from intrinsic instability, leading to low yield, inconsistent size and structure, and susceptibility to agglomeration, oxidation, and sintering. We propose a novel concept: employing oxidized metal atomic clusters as dopants in oxygen-bearing materials, such as oxide dispersion strengthened (ODS) alloys, oxide-based cermets, and toughening ceramics. Using ODS alloy as a proof-of-concept, Ni-NiO coupled cluster-strengthened metallic Ni exhibits finer grains, a larger proportion of low-angle grain boundaries, higher geometrically necessary dislocation density, and achieves a 38% enhancement in Vickers hardness. To advance this concept, four critical scientific issues require resolution: oxidation control, disaggregation and dispersion, effectiveness comparison, and physicochemical behaviors and mechanisms. This work bridges the gap between atomic-level manufacturing and structural materials, offering a pathway to overcome the instability of metal clusters by leveraging their oxidation characteristics.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3649-0
Injectable hydrogels formed via dynamic chemical crosslinks hold great promise as drug delivery platforms due to their robust yet adaptable nature, stimuli-responsiveness, and tunable structures and properties. However, their inherently high water content poses a significant challenge for the efficient encapsulation and sustained release of hydrophobic drugs. Here, we present a novel injectable hydrogel system constructed via a strain-promoted disulfide-thiol exchange between dithiolane-functionalized polymer strands and thiolated core-shell nanoparticles (NPs) under physiological conditions. The hydrophobic core and hydrophilic shell structure of the NPs enables effective loading and protection of hydrophobic drugs, while rapid gelation occurs upon mixing the thiolated NPs with dithiolane-polymers in phosphate-buffered saline. The hydrogel shows excellent injectability, self-healing capability, in vitro biodegradability, and cytocompatibility. This hydrogel system enables sustained release of hydrophobic drugs over 32 days in aqueous media and supports sequential dual-drug release. Its redox-responsiveness under tumor-mimicking reducing conditions, enabled by the disulfide crosslinks, further facilitates controlled intracellular drug release. This multi-component platform offers a versatile strategy for designing advanced injectable hydrogels with potential applications in hydrophobic drug delivery and other biomedical fields.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3773-7
Kesterite Cu2ZnSn(S,Se)4 (CZTSSe) solar cells suffer from significant open-circuit voltage (VOC) deficits due to severe interfacial and bulk recombination, restricting their power conversion efficiency (PCE) far below the Shockley-Queisser limit. This work proposes a low-temperature annealing strategy during ITO sputtering (SA) to synergistically address these challenges. The temperature applied during ITO sputtering not only improves the crystallinity, carrier concentration, and optical transmittance of the ITO layer but also promotes the diffusion of In from ITO into both CdS and CZTSSe layers. Consequently, lattice matching at the CZTSSe/CdS interface is optimized, enabling epitaxial growth. And a favorable ITO/In:CdS/In&Cd:CZTSSe structure with optimal band alignment is obtained. As a result, a champion device with a PCE of 14.29% was achieved. The SA-treating also enabled the CZTSSe solar cells to achieve the highest VOC reported to date, exceeding 590 mV. This underscores the essential role of SA processing in optimizing interface engineering and suppressing defects, thus promoting the development of low-cost, high-performance kesterite photovoltaics.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3882-y
Organic semiconductor crystals with well-defined morphologies are highly desirable for high-performance optoelectronic devices, yet precise control over their growth remains a challenge. Here, a novel donor-acceptor (D-A) molecule, TQDPT, has been successfully developed, featuring a rigid π-conjugated acceptor core composed of thiazoloquinoxaline and naphthalene, coupled with phenylphenothiazine donors. This study presents a temperature-mediated crystallization strategy for precisely controlling the morphology and carrier transport properties of TQDPT single crystals. By systematically investigating the growth kinetics across a controlled temperature range (15–35°C), we reveal a distinct transition from needle-like structures to plate-like crystals, with tunable average widths spanning from around 2.8 to 30.1 μm. This morphological evolution is driven by temperature-dependent molecular diffusion and nucleation kinetics. Significantly, the plate-like crystals grown at 25°C exhibit an order-of-magnitude enhancement in mobility compared to needle-like counterparts, while higher temperatures of 35°C yield broader crystals with improved carrier mobility and device stability. This work highlights the critical role of temperature as a pivotal parameter in the dimensional and electronic optimization of organic crystals, offering an attractive approach to optimize functional materials for advanced optoelectronics.