{"title":"A Novel Microsteganography Technique Leveraging Engineered Relaxation Pathways of High-Energy Excitons in Monolayer WSe2","authors":"Chuxin Yan, Baiyang Sun, Yuanzheng Li, Rui Li, Qingbin Wang, Yongsheng Gao, Wei Xin, Weizhen Liu, Haiyang Xu, Yichun Liu","doi":"10.1021/acs.nanolett.5c01706","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c01706","url":null,"abstract":"In the age of information overload, protecting sensitive data demands reliable solutions, with multidimensional optical encryption emerging as a transformative technology. Wavelength, a critical parameter of light, holds significant potential for developing highly secure encryption systems that restrict information access to specific illumination conditions, further enhancing data security. However, the encryption technology related to wavelength is still in its nascent stages. Here, we report a breakthrough wavelength-dependent microsteganography technique based on a monolayer WSe<sub>2</sub>/CdSe quantum dots heterostructure. By precise modulation of the band alignment to engineer the relaxation pathways of high-energy excitons in WSe<sub>2</sub>, the heterostructure encodes information that is selectively activated by a specific wavelength of light. Furthermore, the incorporation of Morse code encryption seamlessly merges spectral selectivity with enhanced information complexity, creating a dual-layer security mechanism. This work not only advances the field of optical encryption but also opens new avenues for applications in secure data storage and transmission.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"147 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nano LettersPub Date : 2025-05-29DOI: 10.1021/acs.nanolett.5c01808
Linglong Zhang, Fan Yang, Fuguo Tian, Yichun Cui, Kan Zhou, Tong Tong, Haizeng Song, Zhixing Gan, Han Yan, Xueqian Sun, ShunShun Yang, Rui Fang, Jiong Yang, Neng Wan, Yangyang Fu, Hucheng Song, Yongbiao Zhai, Youwen Liu, Yi Shi, Yuerui Lu
{"title":"Harnessing Atomic-Scale Thinning in Two-Dimensional Organic Molecular Crystals for In-Situ Characterization and Superior Optoelectronics","authors":"Linglong Zhang, Fan Yang, Fuguo Tian, Yichun Cui, Kan Zhou, Tong Tong, Haizeng Song, Zhixing Gan, Han Yan, Xueqian Sun, ShunShun Yang, Rui Fang, Jiong Yang, Neng Wan, Yangyang Fu, Hucheng Song, Yongbiao Zhai, Youwen Liu, Yi Shi, Yuerui Lu","doi":"10.1021/acs.nanolett.5c01808","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c01808","url":null,"abstract":"Two-dimensional organic single crystals (2D OSCs) offer high crystallinity and quantum limit properties, making them ideal for exploring unique quantum phases and developing scaled optoelectronic devices. However, accurately probing the structure-optoelectronic relationship in 2D OSCs remains challenging. Here we realize in situ optoelectronic characterization of 2D OSCs through an atomically precise thinning technique. Thinning 3D pentacene crystals to the monolayer limit induces a phase transition from Frenkel excitons to charge-transfer (CT) excitons, achieving a near-unity quantum yield (∼95.1%). In-situ electrical measurements demonstrate that this thinning improves carrier mobility and reduces threshold voltages. Utilizing 2D pentacene crystals, we construct a high-performance synapse device, showing a record paired-pulse facilitation index (PPF index ∼ 261%). This remarkable synaptic plasticity further allows us to emulate the human vision system, predicting the object trajectory with exceptional accuracy (∼99.1%). These results provide new insights into the intrinsic properties of 2D OSCs and lay the foundation for multifunctional optoelectronic applications.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"424 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nano LettersPub Date : 2025-05-28DOI: 10.1021/acs.nanolett.5c01771
Bo Jiang, Niu Pan, Zixiao Wang, Hui Wang
{"title":"Imaging the Thermal Dynamic Panorama for Volume Phase Transition and Water-Molecule Communication of Single Microhydrogels","authors":"Bo Jiang, Niu Pan, Zixiao Wang, Hui Wang","doi":"10.1021/acs.nanolett.5c01771","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c01771","url":null,"abstract":"Thermal volume phase transition of thermosensitive hydrogels, the intrinsic stress-stimulated response of the microstructure, is widely utilized to fabricate flexible smart devices. However, their stability and responsiveness are limited by mechanical properties linked to size, water content, and polymer chain deformation. Herein, we employed a synchronous thermal–optical imaging technique to <i>in situ</i> investigate the volume phase transition behaviors of a single microhydrogel under thermal cycling. At the single-microhydrogel level, we found that hysteretic dynamics within the low critical solution temperature region revealed distinct collapse/swell mechanisms tied to water-molecule communication and microscale morphology. Furthermore, the hydrophilicity of a substrate regulates the microgel mobility, affecting water transport and intermicrogel communication. Additionally, microgel water-molecule communication enables infiltration on superhydrophobic surfaces like lotus leaves. This thermal-controlled optical imaging methodology greatly develops a serviceable characterization of flexible stimuli-driven materials and devices at the microentity level, decoding their detailed dynamic processes, transient intermediate states, and intrinsic mechanisms.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"68 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nano LettersPub Date : 2025-05-28DOI: 10.1021/acs.nanolett.5c01788
Jingxin Chen, Jin Young Oh, Boyu Li, Zhihan Qiao, Haiyang Zhang, Deyang Li, Enyang Men, Hangtian Wang, Shibo Xi, Kai Chen, Han Zhang, Hyoungjeen Jeen, Sang-Youn Park, Dongsheng Song, Hong Zhu, Woo Seok Choi, Lin Hao
{"title":"Wavelength-Selective Control of Visible Light Absorption through Capping-Assisted Oxygen Migration in Oxide Heterostructures","authors":"Jingxin Chen, Jin Young Oh, Boyu Li, Zhihan Qiao, Haiyang Zhang, Deyang Li, Enyang Men, Hangtian Wang, Shibo Xi, Kai Chen, Han Zhang, Hyoungjeen Jeen, Sang-Youn Park, Dongsheng Song, Hong Zhu, Woo Seok Choi, Lin Hao","doi":"10.1021/acs.nanolett.5c01788","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c01788","url":null,"abstract":"Oxygen concentration critically determines the physical properties of transition metal oxides. In this work, we realized a subtle modulation of the oxygen concentration in heterostructures composed of perovskite SrTiO<sub>3</sub> (STO) and brownmillerite SrCoO<sub>2.5</sub> (BM-SCO) by deliberately promoting oxygen migration from the oxygen reservoir to BM-SCO with the assistance of STO capping. A small increase in the oxygen concentration was demonstrated to exclusively change the interorbital transition that is mostly related to the O 2p states in BM-SCO. The independent tuning of interorbital transition facilitates a wavelength-selective control of visible-light absorption. This results in a rich colorful appearance of the heterostructures, which depends on the thickness of the STO capping layer. The capping-assisted oxygen migration is expected to facilitate the designing and tailoring of emergent phenomena in oxygen-deficient oxides, even in the absence of a full topotactic phase transition.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"49 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nano LettersPub Date : 2025-05-28DOI: 10.1021/acs.nanolett.4c06306
Qi Jia, Onri J. Benally, Brandon Zink, Delin Zhang, Yang Lv, Shuang Liang, Deyuan Lyu, Yu-Chia Chen, Yifei Yang, Yu Han Huang, Jian-Ping Wang
{"title":"Energy-Efficient Stochastic Signal Manipulation in Superparamagnetic Tunnel Junctions via Voltage-Controlled Exchange Coupling","authors":"Qi Jia, Onri J. Benally, Brandon Zink, Delin Zhang, Yang Lv, Shuang Liang, Deyuan Lyu, Yu-Chia Chen, Yifei Yang, Yu Han Huang, Jian-Ping Wang","doi":"10.1021/acs.nanolett.4c06306","DOIUrl":"https://doi.org/10.1021/acs.nanolett.4c06306","url":null,"abstract":"Superparamagnetic tunnel junctions (sMTJs) are emerging as promising components for stochastic units in neuromorphic computing owing to their tunable random switching behavior. Conventional MTJ control methods, such as spin-transfer torque (STT) and spin–orbit torque (SOT), often require substantial power. Here, we introduce the voltage-controlled exchange coupling (VCEC) mechanism, enabling the switching between antiparallel and parallel states in sMTJs with an ultralow power consumption of only 40 nW, approximately 2 orders of magnitude lower than conventional STT-based sMTJs. This mechanism yields a sigmoid-shaped output response, making it ideally suited to neuromorphic computing applications. Furthermore, we validate the feasibility of integrating VCEC with SOT current control, offering an additional dimension for magnetic state manipulation. This work marks the first practical demonstration of the VCEC effect in sMTJs, highlighting its potential as a low-power control solution for probabilistic bits in advanced computing systems.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"244 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Superior Hydrogen Separation in Nanofluidic Membranes by Synergistic Effect of Pore Tailoring and Host–Guest Interaction","authors":"Huijie Wang, Miaomiao Shi, Chong Wang, Zhenyu Chu, Zongyou Yin, Chen Wang","doi":"10.1021/acs.nanolett.5c01736","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c01736","url":null,"abstract":"High-purity H<sub>2</sub> production accompanied by precise decarbonization paves the way for a carbon-neutral society. Hydrogen-bonded organic frameworks (HOFs) are promising materials for advanced gas separation membranes, but their broad nanoscale pores limit selective separation. High-quality carboxylic acid-based HOF membranes (HOF-S, HOF-M, HOF-L) with pore sizes of 6.2, 16, and 24 Å were synthesized using an innovative pore-tailoring strategy. Under optimized conditions, H<sub>2</sub> can pass through while CO<sub>2</sub> is blocked by the size-exclusion principle. Abundant carboxylic acid groups in pores hinder the mobility of CO<sub>2</sub> via electrostatic interaction, integrating adsorption and molecular sieving to enable excellent H<sub>2</sub> transport and separation. The HOF-S membrane combines size exclusion and HOF-CO<sub>2</sub> interactions, exhibiting excellent selectivity for H<sub>2</sub>/CO<sub>2</sub> (164) and a ternary gas mixture (H<sub>2</sub>/CO<sub>2</sub> selectivity: 154; H<sub>2</sub>/CH<sub>4</sub> selectivity: 201). It also displays long-term stability under both dry and wet conditions. This strategy opens new possibilities for customizing nanofluidic membranes for advanced gas separation technologies.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"58 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Electron Cloaking in MoS2 for High-Performance Optoelectronics","authors":"Yu-Xiang Chen, Jian-Jhang Lee, Ding-Rui Chen, You-Chen Lin, Hao-Ting Chin, Xiu-Yu Huang, Sheng-Kuei Chiu, Chu-Chi Ting, Mario Hofmann, Ya-Ping Hsieh","doi":"10.1021/acs.nanolett.5c02169","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c02169","url":null,"abstract":"Defects in two-dimensional (2D) materials represent both challenges and opportunities to their optoelectronic performance. While defects limit the carrier mobility in transistors through increased charge scattering, they also enhance 2D material functionality in sensors. Electron cloaking, a process that reduces Coulomb scattering via localized electron–defect interactions, has recently been shown to mitigate the performance degradation of bulk semiconductors in the presence of defects. We demonstrate the realization of electron cloaking in 2D materials through the metal decoration of defects. Sulfur vacancies were introduced in MoS<sub>2</sub> and selectively decorated with aluminum using atomic layer deposition. Theoretical and experimental characterization demonstrate the suppression of electronic scattering through localized interactions. Optoelectronic measurements reveal a significant improvement in carrier mobility and lifetime, highlighting the effectiveness of the cloaking mechanism. Our findings open a route independently to maximize performance and functionality of optoelectronic devices, which is illustrated by the realization photosensors with unprecedented sensitivity and speed.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"125 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nano LettersPub Date : 2025-05-28DOI: 10.1021/acs.nanolett.5c01709
Zhiwei Ma, Pengfei Lv, Xin He, Feng Wang, Yongguang Li, Guanjun Xiao, Bo Zou
{"title":"Self-Trapped Excitons or Bi3+ Ions for Broad Emission in a Lead-Free Double Perovskite? Hearing What Pressure Says","authors":"Zhiwei Ma, Pengfei Lv, Xin He, Feng Wang, Yongguang Li, Guanjun Xiao, Bo Zou","doi":"10.1021/acs.nanolett.5c01709","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c01709","url":null,"abstract":"The broad emission origin of lead-free double perovskites with ns<sup>2</sup>-metal ion doping remains a long-standing controversy. Herein, pressure is introduced as a robust tool to determine the mechanism of broad emission from Cs<sub>2</sub>AgIn<sub>0.9</sub>Bi<sub>0.1</sub>Cl<sub>6</sub> nanocrystals (NCs). The negative correlation between the crystal field strength and broad emission wavelength under compression corroborates that the broad emission is indeed attributed to the radiative recombination of self-trapped excitons, ruling out Bi<sup>3+</sup> emission from <sup>3</sup>P<sub><i>n</i></sub> (<i>n</i> = 0, 1, or 2) to <sup>1</sup>S<sub>0</sub> as an alternative mechanism. The broad emission is composed of two types of self-trapped states due to the different structures of BiCl<sub>6</sub>–AgCl<sub>6</sub> and InCl<sub>6</sub>–AgCl<sub>6</sub>. The abnormal emission enhancement within the range of 5.01–10.01 GPa results from the local distortion of BiCl<sub>6</sub> octahedra that increases the exciton–phonon coupling strength. Our study elucidates the long-term dispute about the origin of broad emission in Cs<sub>2</sub>AgIn<sub>0.9</sub>Bi<sub>0.1</sub>Cl<sub>6</sub> NCs, representing a significant step forward in the precise design and synthesis of targeted lead-free double perovskite materials.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"14 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nano LettersPub Date : 2025-05-27DOI: 10.1021/acs.nanolett.5c00195
Kamal Das, Yufei Zhao, Binghai Yan
{"title":"Surface-Dominated Quantum-Metric-Induced Nonlinear Transport in the Layered Antiferromagnet CrSBr","authors":"Kamal Das, Yufei Zhao, Binghai Yan","doi":"10.1021/acs.nanolett.5c00195","DOIUrl":"https://doi.org/10.1021/acs.nanolett.5c00195","url":null,"abstract":"The van der Waals (vdW) antiferromagnet CrSBr has recently garnered significant attention due to its air stability, high magnetic transition temperature, and semiconducting properties. We investigate its nonlinear transport properties and identify a quantum-metric-dipole (QMD)-induced nonlinear anomalous Hall effect and nonlinear longitudinal resistivity, which switch signs upon reversing the Néel vector. The significant QMD originates from Dirac nodal lines near the conduction band edge within the experimentally achievable doping range. Knowing the weak interlayer coupling, it is unexpected that the nonlinear conductivities do not scale with the sample thickness but are dominantly contributed by surface layers. In the electron-doped region, the top layer dominates the response, while the top three layers contribute the most in the hole-doped region. Our results establish topological nodal lines as a guiding principle to design high-performance nonlinear quantum materials, and we suggest that surface-sensitive transport devices will provide new avenues for nonlinear electronic applications.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"3 1","pages":""},"PeriodicalIF":10.8,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}