ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Li Yang,Hao Wu,Liang Zhang,Gaojie Zhang,Hongda Li,Wen Jin,Wenfeng Zhang,Haixin Chang
The intrinsically nonmagnetic feature of van der Waals (vdW) layered transition-metal dichalcogenide (TMDC) semiconductors limits the spintronic applications of these semiconductors. In this paper, we demonstrate a facile Te flux strategy to induce intrinsic ferromagnetism in the vdW layered 2H-MoTe2 semiconductor by magnetic chromium (Cr) doping. The Curie temperature (Tc) and saturation magnetization (Ms) can be well tuned by adjusting the Cr doping concentration. A notable Tc up to 275 K can be achieved for the vdW layered Cr-doped 2H-MoTe2 bulk crystals, which is much higher than that of recently reported van der Waals ferromagnetic semiconductors (Tc is mostly less than 70 K), in contrast to the diamagnetic feature of the pristine MoTe2. Meanwhile, the highest Ms of the vdW layered Cr-doped 2H-MoTe2 bulk crystals can reach 4.78 emu g–1, which is stronger than most values reported for magnetic-element-doped van der Waals materials. In addition, all of the as-grown semiconducting Cr-doped 2H-MoTe2 (Cr-2H-MoTe2) single crystals display a large magnetic anisotropy with an out-of-plane easy axis of magnetization. The observed ferromagnetism in the Cr-2H-MoTe2 has intrinsic characteristics, which can be mainly attributed to the spin polarization caused by Cr doping as confirmed by the density functional theory (DFT) calculations. Our approach offers an avenue to tune the ferromagnetism in the vdW layered semiconductor and explore its diverse spintronic and magnetoelectric applications.
研究领域:
材料科学
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凝聚态物理
·
自旋电子学
✓ 已验证
DOI
高影响因子
ACS Nano
·
2025
·
IF 16
Yao Yao,Yue Zhao,Huijuan Zhang,Wenting Pan,Wei Liang,Yijian Jiang,Xinlong Yan,Yinzhou Yan
The development of surface-enhanced Raman spectroscopy (SERS) as an ultrasensitive fingerprint analysis technique in precision medicine requires high-performance SERS substrates with controllable nanostructure (hot-spot) distribution, simple fabrication, superior stability, biocompatibility, and extraordinary optical responses. Unfortunately, fabrication of arbitrary nanostructures with high homogeneity on a large scale for SERS is still challenging. Herein, we report an ultrafast laser parallel fabrication protocol for Au/2D-transition-metal dichalcogenide hybrid SERS biosensors. The leveraged photonic nanojets (PNJs) are generated by a micron-sized microsphere monolayer to simultaneously trigger localized phase transition in 2H-MoTe2, achieving a 1T′-MoTe2 nanopattern array with a density of 1 million per mm2 by a single laser shot. The Au nanoparticle clusters (AuNCs) are subsequently grown in situ from the 1T′ regions, creating a AuNCs on 1T′/2H-MoTe2 (AuNCs@1T’/2H-MoTe2) hybrid SERS substrate. The fabricated feature diameter and overlay accuracy of the patterned AuNCs are 210.1 ± 3.4 and 9.2 ± 1.7 nm, respectively. To eliminate background noise, we designed dimer-AuNCs@1T′/2H-MoTe2 (dAuNCs@1T′/2H-MoTe2), achieving a detection limit of 10–13 M with an enhancement factor of 4.9 × 108 for the methylene blue (MB) analyte. The strong localized surface plasmon resonances in the dAuNCs as well as efficient charge transfers between Au, 2H-MoTe2, and MB contribute to the majority of Raman enhancement. The multiscale dAuNCs@1T′/2H-MoTe2 array provides a powerful SERSome (comprising multiple SERS spectra) platform for therapeutic drug monitoring, by which we successfully identified the metabolic behaviors of living gastric adenocarcinoma cells administered with two drugs, i.e., capecitabine, oxaliplatin, and their combination. The present work establishes opportunities for creating a highly ordered nanopattern array for ultrasensitive SERSome analysis of cell metabolism in cancer therapy.
研究领域:
纳米技术
·
生物医学工程
·
分析化学
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癌症研究
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材料科学
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光学与光子学
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精准医学
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产品关联
DOI
PubMed
高影响因子
Science China-Materials
·
2021
·Vol. 64
·期 9
·2202-2211
·
IF 8.273
Wang Yaqian,Shen Yongli,Xiao Xiong,Dai Linxiu,Yao Shuang,An Changhua
Metastable 1T′ MoTe 2 has attracted much attention as a cost-effective electrocatalyst for hydrogen evolution reaction (HER) in recent years. However, few studies were done over common stable 2H phase because it often exhibits inferior performance. Herein, stable 2H MoTe 2 with S-doped Te vacancies has been synthesized by one-step telluride conversion of 1T MoS 2 at 700°C under Ar/H 2 atmosphere. It is demonstrated that the synergistic effect of S-doping and Te vacancies changes the electronic structures of the catalyst. Density functional theory (DFT) studies show that plentiful electrons accumulate on the surface S atoms in S-doped Te vacancies of 2H MoTe 2 catalyst, which may be as active sites to promote HER. Moreover, the as-synthesized catalyst can be directly used as working electrode, and realizes current density of 100 mA cm −2 at overpotential of 217 mV with Tafel slope of 94 mV dec −1 . This work stimulates intensive studies on the activation of inert phase of other nanocatalysts towards various reactions.
✓ 已验证
DOI
高影响因子
ADVANCED MATERIALS
·
2024
·Vol. 37
·期 23
·2404013
·
IF 27.4
Yunxia Hu,Jun Wang,Mohsen Tamtaji,Yuan Feng,Tsz Wing Tang,Mohammadreza Amjadian,Ting Kang,Mengyang Xu,Xingyi Shi,Dongxu Zhao,Yongli Mi,Zhengtang Luo,Liang An
Van der Waals junctions hold significant potentials for various applications in multifunctional and low-power electronics and optoelectronics. The multistep device fabrication process usually introduces lattice mismatch and defects at the junction interfaces, which deteriorate device performance. Here the layer engineering synthesis of van der Waals homojunctions consisting of 2H-MoTe 2 with asymmetric thickness to eliminate heterogenous interfaces and thus obtain clean interfaces is reported. Experimental results confirm that the homostructure nature gives rise to the formation of pristine van der Waals junctions, avoiding chemical disorders and defects. The ability to tune the energy bands of 2H-MoTe 2 continuously through layer engineering enables the creation of adjustable built-in electric field at the homojunction boundaries, which leads to the achievement of self-powered photodetection based on the obtained 2H-MoTe 2 films. Furthermore, the successful integration of 2H-MoTe 2 homojunctions into an image sensor with 10 × 10 pixels, brings about zero-power consumption and near-infrared imaging functions. The pristine van der Waals homojunctions and effective integration strategies shed new insights into the development of large-scale application for two-dimensional materials in advanced electronics and optoelectronics.
研究领域:
光电子学
·
纳米电子学
·
二维材料
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半导体器件
·
图像传感技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）