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1.
JPRAS Open ; 41: 4-8, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38784717

RESUMO

Onycholemmal carcinoma is characterized as a slowly progressing malignant tumor originating from the epithelium of the nail bed. A limited number of cases have been documented in the English literature. The majority of the patients included in the reports underwent amputation of the affected phalanx, and no instances of recurrence were noted during the follow-up period. A 61-year-old Chinese male presented with a persistent ulceration on the nail bed of the right great toe. Microscopic analysis indicated the presence of an epithelial tumor consisting of small keratocysts with sudden central keratinization and atypical keratinocyte nests that were devoid of a granular layer. The tumor exhibited infiltrative growth within the dermis, displaying a multilobulated pattern, but did not extend into the distal phalangeal bone. Based on these findings, the diagnosis of onycholemmal carcinoma was made for this case. All documented cases indicate that onycholemmal carcinoma is a rare malignant tumor originating from the nail bed epithelium, and its clinical progression is typically slow and non-aggressive. This case is presented to provide an analysis of the clinical and pathological features of onycholemmal carcinoma, aiming to assist in the clinical selection of treatment options.

2.
Ecotoxicol Environ Saf ; 277: 116343, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38657456

RESUMO

Curcumin (CUR) is a compound extracted from turmeric that has a variety of functions including antioxidant and anti-inflammatory. As an estrogen-like mycotoxin, zearalenone (ZEN) not only attacks the reproductive system, but also has toxic effects on the liver. However, whether CUR can alleviate ZEN-induced liver injury remains unclear. This paper aims to investigate the protective effect of CUR against ZEN-induced liver injury in mice and explore the molecular mechanism involved. BALB/c mice were randomly divided into control (CON) group, CUR group (200 mg/kg b. w. CUR), ZEN group (40 mg/kg b. w. ZEN) and CUR+ZEN group (200 mg/kg b. w. CUR+40 mg/kg b. w. ZEN). 28 d after ZEN exposure and CUR treatment, blood and liver samples were collected for subsequent testing. The results showed that CUR reversed ZEN-induced hepatocyte swelling and necrosis in mice. It significantly reduced the serum alkaline phosphatase (ALP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in mice (p < 0.05). In addition, CUR significantly reduced hepatic ROS, malondialdehyde, hydrogen peroxide and apoptosis levels in mice (p < 0.05). Quantitative RT-PCR and Western blot results showed that CUR significantly reduced the expression of Bax and Caspase3, and reversed the increase of Nrf2, HO-1 and NQO1 expression in the liver of mice induced by ZEN (p < 0.05). In conclusion, CUR alleviated ZEN-induced liver injury in mice by scavenging ROS and inhibiting the mitochondrial apoptotic pathway.


Assuntos
Apoptose , Doença Hepática Induzida por Substâncias e Drogas , Curcumina , Camundongos Endogâmicos BALB C , Espécies Reativas de Oxigênio , Zearalenona , Animais , Zearalenona/toxicidade , Curcumina/farmacologia , Apoptose/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Camundongos , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Mitocôndrias/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/patologia , Fígado/metabolismo , Masculino , Estresse Oxidativo/efeitos dos fármacos , Antioxidantes/farmacologia
3.
Nano Lett ; 24(3): 983-992, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38206182

RESUMO

On-chip polarization detectors have attracted extensive research interest due to their filterless and ultracompact architecture. However, their polarization-dependent photoresponses cannot be dynamically adjusted, hindering the development toward intelligence. Here, we propose dynamically reconfigurable polarimetry based on in-sensor differentiation of two self-powered photoresponses with orthogonal polarization dependences and tunable responsivities. Such a device can be electrostatically configured in an ultrahigh polarization extinction ratio (PER) mode, where the PER tends to infinity, a Stokes parameter direct sensing mode, where the photoresponse is proportional to S1 or S2 with high accuracy (RMSES1 = 1.5%, RMSES2 = 2.0%), or a background suppressing mode, where the target-background polarization contrast is singularly enhanced. Moreover, the device achieves a polarization angle sensitivity of 0.51 mA·W-1·degree-1 and a specific polarization angle detectivity of 2.8 × 105 cm·Hz1/2·W·degree-1. This scheme is demonstrated throughout the near-to-long-wavelength infrared range, and it will bring a leap for next-generation on-chip polarimeters.

4.
Nanoscale ; 15(45): 18306-18316, 2023 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-37920997

RESUMO

Two-dimensional (2D) ferroelectric semiconductors, such as α-In2Se3 with switchable spontaneous polarization and superior optoelectronic properties, exhibit large potential for functional device applications. The electric transport properties and device performance of 2D α-In2Se3 are strongly sensitive to the ferroelectric domain structures and polarization textures, but they are rarely explored at the atomic scale. Herein, by a combination of first-principles calculations and a developed domain switching theory, we report the domain nucleation kinetics and polarization-texture dependent electronic properties in α-In2Se3 ferroelectrics. Our calculated results reveal that the reversed domains characterized by armchair boundaries tend to form triangular or stripped shape. The energy barrier for propagating domain boundaries is ∼1.42 eV and can be reduced by loading external electric field, which is responsible for driving the evolution of domain structures. Moreover, the domain switching leads to notable changes in the band gap and carrier spatial distribution of α-In2Se3 monolayer, resulting in higher electric resistance of multi-polarization domain structures than that of single-polarization state. The domain structures of multilayer α-In2Se3 follow a layer-by-layer switching mechanism, which causes the transition of electronic structures from self-doped p-n junctions to type-II semiconductor homojunctions. This study not only provides an in-depth insight into the domain switching mechanisms of α-In2Se3 but also opens up the possibility to tailor their electronic and transport properties.

5.
Nano Lett ; 23(19): 9105-9113, 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37694889

RESUMO

Achieving perfect absorption in few-layer two-dimensional (2D) materials plays a crucial role in applications such as optoelectronics and sensing. However, the underlying mechanisms of all reported works imply a strongly inherent dependence of the central wavelength on the structural parameters. Here, we propose a structure-parameter-deviation immune method for achieving perfect absorption at any desired wavelength by harnessing the toroidal dipole-bound state in the continuum (TD BIC). We experimentally demonstrate the versatile design with a monolayer-graphene-loaded compound grating structure. Such a TD BIC built upon the TE31 mode allows for the transition from BIC to quasi-BIC without breaking the structural symmetry, enabling the stable resonance wavelength while tailoring the quality factors via variation of the gap distance. Comparison with traditional literature further reveals the superiority of our method in realizing highly robust perfect absorption, with a wavelength stability ratio of >15. Remarkably, this approach can be straightforwardly applied to other 2D materials.

6.
Sci Adv ; 9(36): eadh2358, 2023 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-37682991

RESUMO

H2BK120ub1 triggers several prominent downstream histone modification pathways and changes in chromatin structure, therefore involving it into multiple critical cellular processes including DNA transcription and DNA damage repair. Although it has been reported that H2BK120ub1 is mediated by RNF20/40 and CRL4WDR70, less is known about the underlying regulation mechanism for H2BK120ub1 by WDR70. By using a series of biochemical and cell-based studies, we find that WDR70 promotes H2BK120ub1 by interacting with RNF20/40 complex, and deposition of H2BK120ub1 and H3K79me2 in POLE3 loci is highly sensitive to POLE3 transcription. Moreover, we demonstrate that POLE3 interacts CHRAC1 to promote DNA repair by regulation on the expression of homology-directed repair proteins and KU80 recruitment and identify CHRAC1 D121Y mutation in colorectal cancer, which leads to the defect in DNA repair due to attenuated the interaction with POLE3. These findings highlight a previously unknown role for WDR70 in maintenance of genomic stability and imply POLE3 and CHRAC1 as potential therapeutic targets in cancer.


Assuntos
Quebras de DNA de Cadeia Dupla , Reparo do DNA , Mutação , Processamento de Proteína Pós-Traducional , Reparo de DNA por Recombinação
7.
Adv Mater ; 35(41): e2304161, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37408327

RESUMO

The Jones matrix, with eight degrees of freedom (DoFs), provides a general mathematical framework for the multifunctional design of metasurfaces. Theoretically, the maximum eight DoFs can be further extended in the spectrum dimension to endow unique encryption capabilities. However, the topology and intrinsic spectral responses of meta-atoms constrains the continuous engineering of polarization evolution over wavelength dimension. In this work, a forward evolution strategy to quickly establish the mapping relationships between the solutions of the dispersion Jones matrix and the spectral responses of meta-atoms is reported. Based on the eigenvector transformation method, arbitrary conjugate polarization channels over the continuous-spectrum dimension are successfully reconstructed. As a proof-of-concept, a silicon metadevice is demonstrated for optical information encryption transmission. Remarkably, the arbitrary combination forms of polarization and wavelength dimension increase the information capacity (210 ), and the measured polarization contrasts of the conjugate polarization conversion are >94% in the entire wavelength range (3-4 µm). It is believed that the proposed approach will benefit secure optical and quantum information technologies.

8.
Sensors (Basel) ; 23(12)2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37420534

RESUMO

Studying the nonlinear photoresponse of different materials, including III-V semiconductors, two-dimensional materials and many others, is attracting burgeoning interest in the terahertz (THz) field. Especially, developing field-effect transistor (FET)-based THz detectors with preferred nonlinear plasma-wave mechanisms in terms of high sensitivity, compactness and low cost is a high priority for advancing performance imaging or communication systems in daily life. However, as THz detectors continue to shrink in size, the impact of the hot-electron effect on device performance is impossible to ignore, and the physical process of THz conversion remains elusive. To reveal the underlying microscopic mechanisms, we have implemented drift-diffusion/hydrodynamic models via a self-consistent finite-element solution to understand the dynamics of carriers at the channel and the device structure dependence. By considering the hot-electron effect and doping dependence in our model, the competitive behavior between the nonlinear rectification and hot electron-induced photothermoelectric effect is clearly presented, and it is found that the optimized source doping concentrations can be utilized to reduce the hot-electron effect on the devices. Our results not only provide guidance for further device optimization but can also be extended to other novel electronic systems for studying THz nonlinear rectification.


Assuntos
Semicondutores , Radiação Terahertz , Desenho de Equipamento , Elétrons
9.
Light Sci Appl ; 12(1): 176, 2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37443133

RESUMO

Filterless light-ellipticity-sensitive optoelectronic response generally has low discrimination, thus severely hindering the development of monolithic polarization detectors. Here, we achieve a breakthrough based on a configurable circular-polarization-dependent optoelectronic silent state created by the superposition of two photoresponses with enantiomerically opposite ellipticity dependences. The zero photocurrent and the significantly suppressed noise of the optoelectronic silent state singularly enhance the circular polarization extinction ratio (CPER) and the sensitivity to light ellipticity perturbation. The CPER of our device approaches infinity by the traditional definition. The newly established CPER taking noise into account is 3-4 orders of magnitude higher than those of ordinary integrated circular polarization detectors, and it remains high in an expanded wavelength range. The noise equivalent light ellipticity difference goes below 0.009° Hz-1/2 at modulation frequencies above 1000 Hz by a light power of 281 µW. This scheme brings a leap in developing monolithic ultracompact circular polarization detectors.

10.
Nat Commun ; 14(1): 3433, 2023 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-37301939

RESUMO

High quality(Q) factor optical resonators are indispensable for many photonic devices. While very large Q-factors can be obtained theoretically in guided-mode settings, free-space implementations suffer from various limitations on the narrowest linewidth in real experiments. Here, we propose a simple strategy to enable ultrahigh-Q guided-mode resonances by introducing a patterned perturbation layer on top of a multilayer-waveguide system. We demonstrate that the associated Q-factors are inversely proportional to the perturbation squared while the resonant wavelength can be tuned through material or structural parameters. We experimentally demonstrate such high-Q resonances at telecom wavelengths by patterning a low-index layer on top of a 220 nm silicon on insulator substrate. The measurements show Q-factors up to 2.39 × 105, comparable to the largest Q-factor obtained by topological engineering, while the resonant wavelength is tuned by varying the lattice constant of the top perturbation layer. Our results hold great promise for exciting applications like sensors and filters.


Assuntos
Engenharia , Fótons , Silício , Vibração
11.
Anal Chim Acta ; 1272: 341520, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37355337

RESUMO

Small non-coding RNAs (sncRNAs) consisting of tRNA-derived small RNAs (tsRNAs) and miRNAs can be released by cancer cells and detected in blood, offering great potential for diagnosis of malignant tumors such as squamous cell carcinoma of the esophagus (ESCC). One of the major challenges for the clinical application of blood-based sncRNAs biomarkers is the difficulty of detection because of their small sncRNA size and low abundance. The deferentially expressed tsRNAs and miRNAs in plasma were studied with high-throughput sequencing and polymerase chain reaction in ESCC cohorts. A novel signature containing tRF-55:74-chrM.Phe-GAA, tRF-56:75-Ala-CGC-1-M4 and miR-4488 was identified with diagnostic potential. The signature was further confirmed by an attomolar-level ultrasensitive and rapid microfluidic biochip, which can achieve a multiplex, simple and low-cost detection. Our results indicated that a combination of tsRNAs and miRNAs has high diagnostic efficiency and tremendous potential to act as specific biomarkers through a reliable, highly sensitive, fast, and economic microfluidic biochip for ESCC diagnosis.


Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , MicroRNAs , Pequeno RNA não Traduzido , Humanos , Carcinoma de Células Escamosas do Esôfago/diagnóstico , Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas do Esôfago/patologia , MicroRNAs/genética , Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/genética , Microfluídica , Curva ROC , Biomarcadores Tumorais/genética
12.
Small ; 19(44): e2303675, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37381648

RESUMO

Van der Waals (vdW) metal-semiconductor junctions (MSJs) exhibit huge potential to reduce the contact resistance and suppress the Fermi-level pinning (FLP) for improving the device performance, but they are limited by optional (2D) metals with a wide range of work functions. Here a new class of vdW MSJs entirely composed of atomically thin MXenes is reported. Using high-throughput first-principles calculations, highly stable 80 metals and 13 semiconductors are screened from 2256 MXene structures. The selected MXenes cover a broad range of work functions (1.8-7.4 eV) and bandgaps (0.8-3 eV), providing a versatile material platform for constructing all-MXene vdW MSJs. The contact type of 1040 all-MXene vdW MSJs based on Schottky barrier heights (SBHs) is identified. Unlike conventional 2D vdW MSJs, the formation of all-MXene vdW MSJs leads to interfacial polarization, which is responsible for the FLP and deviation of SBHs from the prediction of Schottky-Mott rule. Based on a set of screening criteria, six Schottky-barrier-free MSJs with weak FLP and high carrier tunneling probability (>50%) are identified. This work offers a new way to realize vdW contacts for the development of high-performance electronic and optoelectronic devices.

13.
Nanotechnology ; 34(37)2023 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-37311451

RESUMO

Highly efficient water electrolytic agents are restricted by the lack of cheap and Earth-abundant catalysts that can manipulate at unharsh conditions and be prepared with a simple procedure. Here, hierarchically vertical and porous MoS2-CoS2heterojunction nanosheet arrays are designed and fabricated. The MoS2-CoS2nanosheets are composed of ultrasmall nanocrytallites with the dimension of ∼62 nm. This special and novel architecture presents synergistic properties to create excellent oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), where high density active sites generated by ultrasmall nanocrytallites with heterostructures, and the vertical and porous structure accelerates electrolyte transport with luxuriant channels while this hierarchically collaborative framework guarantees completely exposed active sites to electrolytes. This electrode shows low overpotentials of 295 and 103 mV at 10 mA cm-2, small Tafel slopes of 70 and 78 mV dec-1, and long stability for OER and HER, respectively. This work indicates that vertical and porous heterojunction nanosheet arrays with hierarchically ultrasmall secondary nanostructures are a promising catalyst for widespread application.


Assuntos
Hidrogênio , Molibdênio , Porosidade , Eletrodos , Oxigênio
14.
Light Sci Appl ; 12(1): 105, 2023 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-37142624

RESUMO

Objects with different shapes, materials and temperatures can emit distinct polarizations and spectral information in mid-infrared band, which provides a unique signature in the transparent window for object identification. However, the crosstalk among various polarization and wavelength channels prevents from accurate mid-infrared detections at high signal-to-noise ratio. Here, we report full-polarization metasurfaces to break the inherent eigen-polarization constraint over the wavelengths in mid-infrared. This recipe enables to select arbitrary orthogonal polarization basis at individual wavelength independently, therefore alleviating the crosstalk and efficiency degradation. A six-channel all-silicon metasurface is specifically presented to project focused mid-infrared light to distinct positions at three wavelengths, each with a pair of arbitrarily chosen orthogonal polarizations. An isolation ratio of 117 between neighboring polarization channels is experimentally recorded, exhibiting detection sensitivity one order of magnitude higher than existing infrared detectors. Remarkably, the high aspect ratio ~30 of our meta-structures manufactured by deep silicon etching technology at temperature -150 °C guarantees the large and precise phase dispersion control over a broadband from 3 to 4.5 µm. We believe our results would benefit the noise-immune mid-infrared detections in remote sensing and space-to-ground communications.

15.
Artigo em Inglês | MEDLINE | ID: mdl-36888888

RESUMO

The epitaxial growth of low-dimensional tin chalcogenides SnX (X = S, Se) with a controlled crystal phase is of particular interest since it can be utilized to tune optoelectronic properties and exploit potential applications. However, it still remains a great challenge to synthesize SnX nanostructures with the same composition but different crystal phases and morphologies. Herein, we report a phase-controlled growth of SnS nanostructures via physical vapor deposition on mica substrates. The phase transition from α-SnS (Pbnm) nanosheets to ß-SnS (Cmcm) nanowires can be tailored by the reduction of growth temperature and precursor concentration, which originates from a delicate competition between SnS-mica interfacial coupling and phase cohesive energy. The phase transition from the α to ß phase not only greatly improves the ambient stability of SnS nanostructures but also leads to the band gap reduction from 1.03 to 0.93 eV, which is responsible for fabricated ß-SnS devices with an ultralow dark current of 21 pA at 1 V, an ultrafast response speed of ≤14 µs, and broadband spectra response from the visible to near-infrared range under ambient condition. A maximum detectivity of the ß-SnS photodetector arrives at 2.01 × 108 Jones, which is about 1 or 2 orders of magnitude larger than that of α-SnS devices. This work provides a new strategy for the phase-controlled growth of SnX nanomaterials for the development of highly stable and high-performance optoelectronic devices.

16.
ACS Omega ; 8(6): 5715-5721, 2023 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-36816647

RESUMO

In this work, the structural parameters and electronic properties of PtX2 and Janus PtXY (X, Y = S, Se, and Te) are studied based on the density functional theory. The phonon spectra and the Born criteria of the elastic constant of these six monolayers confirm their stability. All PtX2 and Janus PtXY monolayers show an outstanding stretchability with Young's modulus ranging from 61.023 to 82.124 N/m, about one-fifth that of graphene and half that of MoS2, suggesting highly flexible materials. Our first-principles calculations reveal that the pristine PtX2 and their Janus counterparts are indirect semiconductors with their band gap ranging from 0.760 to 1.810 eV at the Perdew-Burke-Ernzerhof level (1.128-2.580 eV at the Heyd-Scuseria-Ernzerhof level). By applying biaxial compressive and tensile strain, the electronic properties of all PtX2 and Janus PtXY monolayers are widely tunable. Under small compressive strain, PtX2 and Janus PtXY structures remain indirect semiconductors. PtTe2, PtSeTe, and PtSTe monolayers undergo a semiconducting to metallic transition when the strain reaches -6, -8, and -10%, respectively. Interestingly, there is a transition from the indirect semiconductor to a quasi-direct one for all PtX2 and Janus PtXY monolayers when the tensile strain is applied.

17.
Adv Sci (Weinh) ; 10(11): e2205813, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36782097

RESUMO

Owing to the large built-in field for efficient charge separation, heterostructures facilitate the simultaneous realization of a low dark current and high photocurrent. The lack of an efficient approach to engineer the depletion region formed across the interfaces of heterojunctions owing to doping differences hinders the realization of high-performance van der Waals (vdW) photodetectors. This study proposes a ferroelectric-controlling van der Waals photodetector with vertically stacked two-dimensional (2D) black phosphorus (BP)/indium selenide (In2 Se3 ) to realize high-sensitivity photodetection. The depletion region can be reconstructed by tuning the polarization states generated from the ferroelectric In2 Se3 layers. Further, the energy bands at the heterojunction interfaces can be aligned and flexibly engineered using ferroelectric field control. Fast response, self-driven photodetection, and three-orders-of-magnitude detection improvements are achieved in the switchable visible or near-infrared operation bands. The results of the study are expected to aid in improving the photodetection performance of vdW optoelectronic devices.

18.
Light Sci Appl ; 12(1): 39, 2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36750548

RESUMO

Conventional artificial intelligence (AI) machine vision technology, based on the von Neumann architecture, uses separate sensing, computing, and storage units to process huge amounts of vision data generated in sensory terminals. The frequent movement of redundant data between sensors, processors and memory, however, results in high-power consumption and latency. A more efficient approach is to offload some of the memory and computational tasks to sensor elements that can perceive and process the optical signal simultaneously. Here, we proposed a non-volatile photomemristor, in which the reconfigurable responsivity can be modulated by the charge and/or photon flux through it and further stored in the device. The non-volatile photomemristor has a simple two-terminal architecture, in which photoexcited carriers and oxygen-related ions are coupled, leading to a displaced and pinched hysteresis in the current-voltage characteristics. For the first time, non-volatile photomemristors implement computationally complete logic with photoresponse-stateful operations, for which the same photomemristor serves as both a logic gate and memory, using photoresponse as a physical state variable instead of light, voltage and memresistance. The polarity reversal of photomemristors shows great potential for in-memory sensing and computing with feature extraction and image recognition for neuromorphic vision.

19.
Adv Mater ; 35(10): e2209557, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36633006

RESUMO

The zero-magnetic-field nonlinear Hall effect (NLHE) refers to the second-order transverse current induced by an applied alternating electric field; it indicates the topological properties of inversion-symmetry-breaking crystals. Despite several studies on the NLHE induced by the Berry-curvature dipole in Weyl semimetals, the direct current conversion by rectification is limited to very low driving frequencies and cryogenic temperatures. The nonlinear photoresponse generated by the NLHE at room temperature can be useful for numerous applications in communication, sensing, and photodetection across a high bandwidth. In this study, observations of the second-order NLHE in type-II Dirac semimetal CoTe2 under time-reversal symmetry are reported. This is determined by the disorder-induced extrinsic contribution on the broken-inversion-symmetry surface and room-temperature terahertz rectification without the need for semiconductor junctions or bias voltage. It is shown that remarkable photoresponsivity over 0.1 A W-1 , a response time of approximately 710 ns, and a mean noise equivalent power of 1 pW Hz-1/2 can be achieved at room temperature. The results open a new pathway for low-energy photon harvesting via nonlinear rectification induced by the NLHE in strongly spin-orbit-coupled and inversion-symmetry-breaking systems, promising a considerable impact in the field of infrared/terahertz photonics.

20.
Nanoscale ; 15(4): 1775-1781, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36601861

RESUMO

The unique and excellent optoelectronic properties of graphene make it a promising material for THz detection. However, the huge gap between the atomic thickness of graphene and the long wavelength of THz radiation severely limits the efficiency of light absorption and the photoresponse. Although optical antennas are commonly used to concentrate THz waves into deep subwavelength regions, a large amount of power is re-radiated out as waste rather than being absorbed by the active material. Here, we propose a cavity-antenna hybrid structure to enhance the THz absorption in a graphene flake through interference manipulation and impedance matching. The photoresponse of the device under an impedance-matched condition is 15 times higher than that under an impedance-mismatched condition. The cavity-antenna-coupled graphene THz detector exhibits a responsivity of 10.2 mA W-1 and a noise-equivalent power of 0.92 nW Hz-0.5. The excellent performance of our device makes it one of the best room temperature sub-THz graphene detectors that we investigated. A theoretical model was established to analyze the interaction between the antenna-coupled graphene and the cavity structure. With a combination of both electrostatic doping and interference manipulation, the light coupling management by impedance matching can enhance the absorptance of graphene by more than two orders of magnitude. This work experimentally and theoretically revealed that the cavity-antenna hybrid structure can prominently enhance the responsivity of a tiny piece of graphene in the sub-THz regime. Meanwhile, this strategy can also be applied to enhance the absorptance of other low-dimensional or bulk materials.

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