Browse
Submit Data
Databases
API
Help

Dataset Information

21 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Light helicity detector based on 2D magnetic semiconductor CrI₃.

ABSTRACT: Two-dimensional magnetic semiconductors provide a platform for studying physical phenomena at atomically thin limit, and promise magneto-optoelectronic devices application. Here, we report light helicity detectors based on graphene-CrI₃-graphene vdW heterostructures. We investigate the circularly polarized light excited current and reflective magnetic circular dichroism (RMCD) under various magnetic fields in both monolayer and multilayer CrI₃ devices. The devices exhibit clear helicity-selective photoresponse behavior determined by the magnetic state of CrI₃. We also find abnormal negative photocurrents at higher bias in both monolayer and multilayer CrI₃. A possible explanation is proposed for this phenomenon. Our work reveals the interplay between magnetic and optoelectronic properties in CrI₃ and paves the way to developing spin-optoelectronic devices.

SUBMITTER: Cheng X

PROVIDER: S-EPMC8617301 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Very large tunneling magnetoresistance in layered magnetic semiconductor CrI3.

Project description:Magnetic layered van der Waals crystals are an emerging class of materials giving access to new physical phenomena, as illustrated by the recent observation of 2D ferromagnetism in Cr2Ge2Te6 and CrI3. Of particular interest in semiconductors is the interplay between magnetism and transport, which has remained unexplored. Here we report magneto-transport measurements on exfoliated CrI3 crystals. We find that tunneling conduction in the direction perpendicular to the crystalline planes exhibits a magnetoresistance as large as 10,000%. The evolution of the magnetoresistance with magnetic field and temperature reveals that the phenomenon originates from multiple transitions to different magnetic states, whose possible microscopic nature is discussed on the basis of all existing experimental observations. This observed dependence of the conductance of a tunnel barrier on its magnetic state is a phenomenon that demonstrates the presence of a strong coupling between transport and magnetism in magnetic van der Waals semiconductors.

| S-EPMC6023911 | biostudies-literature

Multiwavelength magnetic coding of helical luminescence in ferromagnetic 2D layered CrI3.

Project description:Two-dimensional (2D) van der Waals (vdW) ferromagnets have opened new avenues for manipulating spin at the limits of single or few atomic layers, and for creating unique magneto-exciton devices through the coupling of ferromagnetic (FM) orders and excitons. However, 2D vdW ferromagnets explored so far have rarely possessed exciton behaviors; to date, FM CrI3 have been revealed to show ligand-field photoluminescence correlated with FM ordering, but typically with a broad emission peak. Here, we report a straightforward approach to realize strong coupling of narrow helical emission and FM orders in CrI3 through microsphere cavity. The resonant whispering-gallery modes (WGM) of SiO2 microspheres cause strong oscillation helical emissions with a full width at half-maximum (FWHM) of ∼5 nm under continuous wave excitation. Reversible magnetic coding of helical luminescence is realized in the range of 950-1100 nm. This work enables numerous opportunities for creating magnetic encoding lasing for photonic integrated chips.

| S-EPMC8718829 | biostudies-literature

Transition Metal Adsorbed-Doped ZnO Monolayer: 2D Dilute Magnetic Semiconductor, Magnetic Mechanism, and Beyond 2D.

Project description:As an improvement over organic or inorganic layered crystals, the synthetic monolayer ZnO(M) inherits semiconductivity and hostability from its bulk, yet it acts as a promising host for dilute magnetic semiconductors. Here, we report the electronic and magnetic properties of ZnO(M) doped with one 3d transition metal ion and simultaneously adsorbed with another 3d transition metal ion. Two sequences are studied, one where the dopant is fixed to Mn and the adsorbate is varied from Sc to Zn and another where the dopant and adsorbate are reversed. First-principles results show that the stable adsorbed-doped systems possess a lower bandgap energy than that of the host. System magnetic moments can be tuned to |5 - x|μB, where x refers to the magnetic moment of the individual 3d atom. An interplay between superexchange and direct exchange yields a ferromagnetic system dually adsorbed-doped with Mn. In addition to a novel material design route, the magnetic interaction mechanism is found beyond two dimensions, having been identified for its three-dimensional bulk and zero-dimensional cluster counterparts.

| S-EPMC6641190 | biostudies-literature

Switchable magnetic bulk photovoltaic effect in the two-dimensional magnet CrI3.

Project description:The bulk photovoltaic effect (BPVE) rectifies light into the dc current in a single-phase material and attracts the interest to design high-efficiency solar cells beyond the pn junction paradigm. Because it is a hot electron effect, the BPVE surpasses the thermodynamic Shockley-Queisser limit to generate above-band-gap photovoltage. While the guiding principle for BPVE materials is to break the crystal centrosymmetry, here we propose a magnetic photogalvanic effect (MPGE) that introduces the magnetism as a key ingredient and induces a giant BPVE. The MPGE emerges from the magnetism-induced asymmetry of the carrier velocity in the band structure. We demonstrate the MPGE in a layered magnetic insulator CrI3, with much larger photoconductivity than any previously reported results. The photocurrent can be reversed and switched by controllable magnetic transitions. Our work paves a pathway to search for magnetic photovoltaic materials and to design switchable devices combining magnetic, electronic, and optical functionalities.

| S-EPMC6706386 | biostudies-literature

Coexistence of structural and magnetic phases in van der Waals magnet CrI3.

Project description:CrI3 has raised as an important system to the emergent field of two-dimensional van der Waals magnetic materials. However, it is still unclear why CrI3 which has a ferromagnetic rhombohedral structure in bulk, changed to anti-ferromagnetic monoclinic at thin layers. Here we show that this behaviour is due to the coexistence of both monoclinic and rhombohedral crystal phases followed by three magnetic transitions at TC1 = 61 K, TC2 = 50 K and TC3 = 25 K. Each transition corresponds to a certain fraction of the magnetically ordered volume as well as monoclinic and rhombohedral proportion. The different phases are continuously accessed as a function of the temperature over a broad range of magnitudes. Our findings suggest that the challenge of understanding the magnetic properties of thin layers CrI3 is in general a coexisting structural-phase problem mediated by the volume-wise competition between magnetic phases already present in bulk.

| S-EPMC8560937 | biostudies-literature

Giant renormalization of dopant impurity levels in 2D semiconductor MoS2.

Project description:Substitutional doping in 2D semiconductor MoS2 was investigated by charge transition level (CTL) calculations for Nitrogen group (N, P, As, Sb) and Halogen group (F, Cl, Br, I) dopants at the S site of monolayer MoS2. Both n-type and p-type dopant levels are calculated to be deep mid-gap states (~1 eV from band edges) from DFT total energy-based CTL and separate DFT + GW calculations. The deep dopant levels result from the giant renormalization of hydrogen-like defect states by reduced dielectric screening in ultrathin 2D films. Theoretical analysis based on Keldysh formulation provides a consistent impurity binding energy of ~1 eV for dielectric thin films. These findings of intrinsic deep impurity levels in 2D semiconductors MoS2 may be applicable to diverse novel emerging device applications.

| S-EPMC7080777 | biostudies-literature

Light absorption engineering of a hybrid (Sn3S72-)n based semiconductor - from violet to red light absorption.

Project description:The crystalline two-dimensional thiostannate Sn3S7(trenH)2 [tren = tris(2-aminoethyl)amine] consists of negatively charged (Sn3S72-)n polymeric sheets with trenH+ molecular species embedded in-between. The semiconducting compound is a violet light absorber with a band gap of 3.0 eV. In this study the compound was synthesized and functionalized by introducing the cationic dyes Methylene Blue (MB) or Safranin T (ST) into the crystal structure by ion exchange. Dye capacities up to approximately 45 mg/g were obtained, leading to major changes of the light absorption properties of the dye stained material. Light absorption was observed in the entire visible light region from red to violet, the red light absorption becoming more substantial with increasing dye content. The ion exchange reaction was followed in detail by variation of solvent, temperature and dye concentration. Time-resolved studies show that the ion exchange follows pseudo-second order kinetics and a Langmuir adsorption mechanism. The pristine and dye stained compounds were characterized by powder X-ray diffraction and scanning electron microscopy revealing that the honeycomb hexagonal pore structure of the host material was maintained by performing the ion exchange in the polar organic solvent acetonitrile, while reactions in water caused a break-down of the long-range ordered structure.

| S-EPMC5379188 | biostudies-literature

Highly-Sensitive Thin Film THz Detector Based on Edge Metal-Semiconductor-Metal Junction.

Project description:Terahertz (THz) detectors have been extensively studied for various applications such as security, wireless communication, and medical imaging. In case of metal-insulator-metal (MIM) tunnel junction THz detector, a small junction area is desirable because the detector response time can be shortened by reducing it. An edge metal-semiconductor-metal (EMSM) junction has been developed with a small junction area controlled precisely by the thicknesses of metal and semiconductor films. The voltage response of the EMSM THz detector shows the clear dependence on the polarization angle of incident THz wave and the responsivity is found to be very high (~2,169 V/W) at 0.4?THz without any antenna and signal amplifier. The EMSM junction structure can be a new and efficient way of fabricating the nonlinear device THz detector with high cut-off frequency relying on extremely small junction area.

| S-EPMC5715053 | biostudies-literature

Plasmonic Metal/Semiconductor Heterostructure for Visible Light-Enhanced H2 Production.

Project description:A plasmonic Ag/Bi2WO6 heterostructure, having Ag NPs deposited on Bi2WO6, is obtained by a hydrothermal and photodeposition method. The synthesized Ag/Bi2WO6 composite exhibits strong visible light absorption with a localized surface plasmon resonance (LSPR) and shows an enhanced photoabsorption property. It is demonstrated that such a Ag/Bi2WO6 heterostructure shows excellent plasmon-enhanced photocatalytic activity in the dehydrogenation of ammonia borane (NH3BH3) solution under visible light irradiation, which is due to the results from the synergetic effect between Ag NPs and emerging W5+ ions. More importantly, the performance of a Ag/Bi2WO6 hybrid is almost eight times higher than that of sole Bi2WO6 nanosheets. The introduction of LSPR of Ag in Bi2WO6 improves the electrical conductivity of the composite and lowers the recombination rate of charge carriers. This study opens up the opportunity of rationally fabricating plasmonic metal/semiconductor heterostructures for highly efficient photocatalysis.

| S-EPMC9330258 | biostudies-literature

2D semiconductor nonlinear plasmonic modulators.

Project description:A plasmonic modulator is a device that controls the amplitude or phase of propagating plasmons. In a pure plasmonic modulator, the presence or absence of a plasmonic pump wave controls the amplitude of a plasmonic probe wave through a channel. This control has to be mediated by an interaction between disparate plasmonic waves, typically requiring the integration of a nonlinear material. In this work, we demonstrate a 2D semiconductor nonlinear plasmonic modulator based on a WSe2 monolayer integrated on top of a lithographically defined metallic waveguide. We utilize the strong interaction between the surface plasmon polaritons (SPPs) and excitons in the WSe2 to give a 73 % change in transmission through the device. We demonstrate control of the propagating SPPs using both optical and SPP pumps, realizing a 2D semiconductor nonlinear plasmonic modulator, with an ultrafast response time of 290?fs.

| S-EPMC6646399 | biostudies-literature