Nano Letters最新文献

Dynamic fluorescent materials are attractive for tunable emission colors, but most multicolor systems are limited by a few switching states and complex modulation. To address these challenges, a composite system (MG-CDs) was designed by embedding aggregation-induced color-tuning carbon dots (CDs) into microgels. When respectively swollen in water (H₂O), ethanol (EtOH), or ethylene glycol (EG), MG-CDs formed distinct internal hydrogen-bonding networks, yielding varied CDs aggregation states and fluorescence emissions. In an H₂O-EtOH-EG cosolvent, MG-CDs established more complex hydrogen-bonding networks and heating-induced solvent volatilization driven hydrogen-bonds reorganization, which simultaneously tuned the CDs aggregation and polymer conformations, endowing diverse thermo-responsive fluorescence transitions and multiple programmable emission states within a unitary system. This mechanism highlighted that coupling solvent-responsive hydrogen-bond regulation in polymer microenvironments with emitter aggregation enables tunable dynamic fluorescence.Furthermore, MG-CDs were used as inks in which a cosolvent treatment and heating-driven printed patterns were used from monochromatic to polychromatic, achieving programmable color evolution for information storage.

Reconfigurable field-effect transistors (RFETs), which allow postfabrication switching of device polarity, are promising candidates for compact and functionally flexible circuit design. Here, we demonstrate large-scale dual n-/p-channel RFETs based on homogeneous monolayer WSe₂, integrated with a charge-trapping layer. Ambipolar transport is achieved by forming parallel n- and p-type conduction paths through selective doping. In addition, a multilayer gate dielectric stack (hBN/HfO₂/Al₂O₃) enables complete nonvolatile switching between n- and p-type modes via charge-trapping. Exploiting this reconfigurability, we realize ternary content-addressable memory using only two RFETs (2T) per cell, where polarity combinations encode the three logic states ('0', '1', and 'X'). Furthermore, a full set of Boolean logic gates─including AND, OR, NAND, and NOR, is demonstrated using series and parallel 2T configurations. These results establish dual n-/p-channel WSe₂ RFETs as scalable and functionally versatile building blocks for programmable logic and memory in future computing architectures.

Motivated by the emerging control of Berry-curvature textures in altermagnets, we explore a two-terminal configuration where a topological-insulator film is interfaced with two altermagnetic electrodes whose crystalline phases can be rotated independently. The proximity coupling imprints each altermagnet's momentum-dependent spin texture onto the Dirac surface states, giving rise to an angular mass whose sign follows the lattice orientation. Adjusting the phase of one electrode redefines this mass pattern, thereby tuning the number and spatial distribution of chiral edge channels. This results in discrete conductance steps and a reversible inversion of the thermoelectric Hall coefficient─achieved without external magnetic fields or net magnetization. A compact Dirac model captures both the quantized switching and its resilience to moderate disorder. Overall, this symmetry-driven mechanism provides a practical and low-dissipation route to programmable topological transport via lattice rotation.

The precise modulation of nanoparticles represents a critical step toward programmable nanodevice architectures and functional material systems. Here, we demonstrate an artificial CeO₂ nanoparticle modulation platform, enabling area-selective manipulation and programmable tunability of the CeO₂ nanoparticle tunneling behavior. Utilizing atomic force microscopy lithography, CeO₂ nanoparticles were attached, detached, and repositioned with nanoscale precision on both insulating and metallic substrates, forming ordered architectures. Sequential strain engineering induces deterministic narrowing of the local density of states, deriving the electronic switching at the single-particle level. Furthermore, vertical 3D stacking of CeO₂ nanoparticle tunneling junctions exhibits designable resonant tunneling and negative differential resistance characteristics, with the threshold strain systematically decreasing with the stacking tier. In conclusion, we envision that our artificial modulation platform provides a systematic foundation for nanoelectronic systems and functional tunneling devices within artificial nanoparticle assemblies.

Bi₂O₂Se is an emerging n-type semiconductor, but conventional growth methods often rely on high temperatures or complex multisource systems that introduce defects and limit device integration. Herein, we report a simplified and modified physical vapor deposition (PVD) strategy enabling the growth of single-crystal Bi₂O₂Se nanosheets at a lower temperature of 500 °C. The self-powered photoelectric detector with an asymmetric structure was fabricated using a Bi₂O₂Se nanosheet as channel material, exhibiting an ultralow dark current of ∼10 fA, weak-light detection capability (50 nW/cm²), and detectivity up to 1.06 × 10¹³ Jones. The devices also show fast response time and excellent long-term stability with <10% degradation after 12 months in the atmospheric environment. Furthermore, single-pixel imaging demonstrates high contrast and fidelity. This work establishes a practical route for low-temperature growth of high-quality Bi₂O₂Se nanosheets and highlights its strong potential for weak-light detection, broadband sensing, and chip-scale photonic systems.