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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.
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BACKGROUND: Exploring the molecular mechanisms of primordial germ cell (PGC) migration and the involvement of gonadal somatic cells in gonad development is valuable for comprehending the origins and potential treatments of reproductive-related diseases. METHODS: Diaphanous related formin 1 (Diaph1, also known as mDia1) was screened by analyzing publicly available datasets (ATAC-seq, DNase-seq, and RNA-seq). Subsequently, the CRISPR-Cas9 technology was used to construct Diaph1 knockout mice to investigate the role of Diaph1 in gonad development. RESULTS: Based on data from public databases, a differentially expressed gene Diaph1, was identified in the migration of mouse PGC. Additionally, the number of PGCs was significantly reduced in Diaph1 knockout mice compared to wild type mice, and the expression levels of genes related to proliferation (Dicer1, Mcm9), adhesion (E-cadherin, Cdh1), and migration (Cxcr4, Hmgcr, Dazl) were significantly decreased. Diaph1 knockout also inhibited Leydig cell proliferation and induced apoptosis in the testis, as well as granulosa cell apoptosis in the ovary. Moreover, the sperm count in the epididymal region and the count of ovarian follicles were significantly reduced in Diaph1 knockout mice, resulting in decreased fertility, concomitant with lowered levels of serum testosterone and estradiol. Further research found that in Diaph1 knockout mice, the key enzymes involved in testosterone synthesis (CYP11A1, 3ß-HSD) were decreased in Leydig cells, and the estradiol-associated factor (FSH receptor, AMH) in granulosa cells were also downregulated. CONCLUSIONS: Overall, our findings indicate that the knockout of Diaph1 can disrupt the expression of factors that regulate sex hormone production, leading to impaired secretion of sex hormones, ultimately resulting in damage to reproductive function. These results provide a new perspective on the molecular mechanisms underlying PGC migration and gonadal development, and offer valuable insights for further research on the causes, diagnosis, and treatment of related diseases.
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Proliferação de Células , Forminas , Células Germinativas , Gônadas , Camundongos Knockout , Animais , Camundongos , Feminino , Masculino , Forminas/genética , Forminas/metabolismo , Proliferação de Células/genética , Gônadas/metabolismo , Células Germinativas/metabolismo , Apoptose/genética , Testículo/metabolismo , Testículo/crescimento & desenvolvimento , Testículo/citologia , Movimento Celular/genética , Ovário/metabolismo , Ovário/crescimento & desenvolvimento , Camundongos Endogâmicos C57BLRESUMO
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 (200â¯mg/kg b. w. CUR), ZEN group (40â¯mg/kg b. w. ZEN) and CUR+ZEN group (200â¯mg/kg b. w. CUR+40â¯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.
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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/farmacologiaRESUMO
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.
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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.
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The exotic electronic properties of topological semimetals (TSs) have opened new pathways for innovative photonic and optoelectronic devices, especially in the highly pursuit terahertz (THz) band. However, in most cases Dirac fermions lay far above or below the Fermi level, thus hindering their successful exploitation for the low-energy photonics. Here, low-energy type-II Dirac fermions in kitkaite (NiTeSe) for ultrasensitive THz detection through metal-topological semimetal-metal heterostructures are exploited. Furthermore, a heterostructure combining two Dirac materials, namely, graphene and NiTeSe, is implemented for a novel photodetector exhibiting a responsivity as high as 1.22 A W-1 , with a response time of 0.6 µs, a noise-equivalent power of 18 pW Hz-0.5 , with outstanding stability in the ambient conditions. This work brings to fruition of Dirac fermiology in THz technology, enabling self-powered, low-power, room-temperature, and ultrafast THz detection.
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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 â¼62 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.
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Hidrogênio , Molibdênio , Porosidade , Eletrodos , OxigênioRESUMO
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.
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Semicondutores , Radiação Terahertz , Desenho de Equipamento , ElétronsRESUMO
Terahertz photodetectors based on emergent intrinsic magnetic topological insulators promise excellent performance in terms of highly sensitive, anisotropic and room-temperature ability benefiting from their extraordinary material properties. Here, we propose and conceive the response features of exfoliated MnBi2Te4 flakes as active materials for terahertz detectors. The MnBi2Te4-based photodetectors show the sensitivity rival with commercially available ones, and the noise equivalent power of 13 pW/Hz0.5 under 0.275 THz at room-temperature led by the nonlinear Hall effect, allowing for the high-resolution terahertz imaging. In addition, a large anisotropy of polarization-dependent terahertz response is observed when the MnBi2Te4 device is tuned into different directions. More interestingly, we discover an unprecedented power-controlled reversal of terahertz response in the MnBi2Te4-graphene device. Our results provide feasibility of manipulating and exploiting the nontrivial topological phenomena of MnBi2Te4 under a high-frequency electromagnetic field, representing the first step toward device implementation of intrinsic magnetic topological insulators.
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Detection of aldehyde carbonyl radiation plays an essential role in guaranteeing the safety of fried food. However, the radiation of low-content aldehyde carbonyl is always weak and includes polarized light. Focusing the weak radiation with polarization-sensitive configurations provides an efficient way to improve the signal-to-noise ratio of detection. The advent of dynamic metasurfaces based on phase-change materials (PCMs) have demonstrated superiorities over their traditional counterparts in tunability and miniaturization. In this paper, we propose two reflected varifocal metasurfaces, which combine Ge2Sb2Se4Te1 (GSST) with two materials that have close optical constants with amorphous and crystalline GSST. The first one realizes a four-spot focal system with linearly-polarized incidence based on polarization multiplexing. It adds a new polarization degree of freedom compared with traditional varifocal metasurfaces. Compared with traditional spatial-multiplexing method, our second metasurface enables the independent control of the polarization and phase profiles of circularly-polarized light. Remarkably, it reduces energy loss and crosstalk. We believe the novel scenarios of combing GSST with similar materials provide a new direction for tunable metasurfaces based on PCMs.
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Multi-resonance light coupling management is a promising way to expand the operating spectral ranges of optoelectronic devices. The classical strategies are either lack of independent tunability for each resonance or involved with complex fabrication. Here, we propose a new scheme for expanding the operating spectral range of an optoelectronic device through a dual-color active material integrated with a simple resonant waveguide structure. The TM waveguide mode and the SPP mode of the resonant waveguide structure are regulated to match the two active regions of the dual-color material both spectrally and spatially. Applying this scheme to a long-wavelength infrared quantum well photodetector, the absorption efficiencies at the two peak detection wavelengths of the dual-color quantum wells are both enhanced by more than 10 times compared with the case of a standard 45° edge facet coupled device with the same detection material. The simple light coupling structure is easy to accomplish and compatible with focal plane arrays. For thermal radiation detection, the absorption efficiency of the 300 K blackbody radiation by our dual-color detector is 83.8% higher than that by a single-color detector with the optimized structural parameters. Moreover, either polarization sensitive or polarization insensitive detection could be achieved in this dual-color infrared quantum well photodetector by using anisotropic or isotropic gratings.
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Using the inherent properties of a heterostructure, ultrafast photodetectors with high sensitivity can be progressively developed that have the potential to carve a niche among the optoelectronic devices. In this Letter, a heterojunction photodetector based on SnSe2/Bi2Se3 is constructed, and a visible-infrared photoresponse with good sensitivity at room temperature is obtained. The SnSe2/Bi2Se3 photodetector demonstrates a high Iph/Id ratio of 1.2 × 104 at 0â V. Moreover, the high responsivity of 2.3 A/W, detectivity of 1.6 × 1011 Jones, and fast response time of 40 µs are simultaneously achieved. The presented results offer an alternative route for ultrafast photodetectors with high sensitivity.
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Benefiting from the inherent capacity for detecting longer wavelengths inaccessible to human eyes, infrared photodetectors have found numerous applications in both military and daily life, such as individual combat weapons, automatic driving sensors and night-vision devices. However, the imperfect material growth and incomplete device manufacturing impose an inevitable restriction on the further improvement of infrared photodetectors. The advent of artificial microstructures, especially metasurfaces, featuring with strong light field enhancement and multifunctional properties in manipulating the light-matter interactions on subwavelength scale, have promised great potential in overcoming the bottlenecks faced by conventional infrared detectors. Additionally, metasurfaces exhibit versatile and flexible integration with existing detection semiconductors. In this paper, we start with a review of conventionally bulky and recently emerging two-dimensional material-based infrared photodetectors, i.e., InGaAs, HgCdTe, graphene, transition metal dichalcogenides and black phosphorus devices. As to the challenges the detectors are facing, we further discuss the recent progress on the metasurfaces integrated on the photodetectors and demonstrate their role in improving device performance. All information provided in this paper aims to open a new way to boost high-performance infrared photodetectors.
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Grafite , Semicondutores , HumanosRESUMO
Circular polarization detection enables a wide range of applications. With the miniaturization of optoelectronic systems, integrated circular polarization detectors with native sensitivity to the spin state of light have become highly sought after. The key issues with this type of device are its low circular polarization extinction ratios (CPERs) and reduced responsivities. Metallic two-dimensional chiral metamaterials have been integrated with detection materials for filterless circular polarization detection. However, the CPERs of such devices are typically below five, and the light absorption in the detection materials is hardly enhanced and is even sometimes reduced. Here, we propose to sandwich multiple quantum wells between a dielectric two-dimensional chiral metamaterial and a metal grating to obtain both a high CPER and a photoresponse enhancement. The dielectric-metal-hybrid chiral metamirror integrated quantum well infrared photodetector (QWIP) exhibits a CPER as high as 100 in the long wave infrared range, exceeding all reported CPERs for integrated circular polarization detectors. The absorption efficiency of this device reaches 54%, which is 17 times higher than that of a standard 45° edge facet coupled device. The circular polarization discrimination is attributed to the interference between the principle-polarization radiation and the cross-polarization radiation of the chiral structure during multiple reflections and the structure-material double polarization selection. The enhanced absorption efficiency is due to the excitation of a surface plasmon polariton wave. The dielectric-metal-hybrid chiral mirror structure is compatible with QWIP focal plane arrays.
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It is challenging to obtain wafer-scaled aligned films for completely exploiting the promising properties of semiconducting single-walled carbon nanotubes (s-SWCNTs). Aligned s-SWCNTs with a large area can be obtained by combining water evaporation and slow withdrawal-induced self-assembly in a dip-coating process. Moreover, the tunability of deposition morphology parameters such as stripe width and spacing is examined. The polarized Raman results show that s-SWCNTs can be aligned in ±8.6°. The derived two terminal photodetector shows both a high negative responsivity of 41 A/W at 520 nm and high polarization sensitivity. Our results indicate that aligned films with a large area may be useful to electronics- and optoelectronics-related applications.
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The avalanche is the foundation of the understanding and vast applications of the breakdown of semiconductors and insulators. Present numerical theories analyzing the avalanche photodetectors are mainly split into two categories: the macroscopic empirical model with fitting parameters and the microscopic process simulation with statistical estimations. Here, we present a parameter-free analytic theory of the avalanche for a narrow-band material, HgCdTe, originated from quantum mechanics, avoiding any fitting parameter or any statistical estimation while taking advantage of both categories. Distinct from classical theory, we propose a full spatial description of an avalanche with basic concepts such as transition rate and equation of motion modified. As a stochastic process, the probability density function (PDF) of impact ionization is utilized in a generalized history-dependent theory. On account of different carrier generation character of light and leakage current, we suggest that carrier generated at different positions should be considered separately, which is done by generalized history-dependent theory in our work. Further, in our calculation, the reason for the abnormal rise of excess noise factor (ENF) observed in the experiment in single-carrier avalanche photodetectors is clarified.
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Inspired by the growing family of Van der Waals materials, hBN supported phonon polaritons have attracted much attention due to their inherent hyperbolic dispersion properties in the mid-infrared. However, the lack of tunability imposes a severe restriction on the diversified, functional and integrated applications. Here, we propose a phase-gradient heterostructure metasurface to realize a dynamically tunable and polarization-sensitive perfect absorber in the mid-infrared through combining hBN and phase change VO2. Narrow-band perfect absorption at 7.2 µm can be switched to broadband around 11.2 µm through controlling the temperature of VO2. The governed physics of the bandwidth and absorption differences are demonstrated. Phonon polaritons in hBN phase-gradient configurations and plasmon polaritons in periodic VO2 blocks are respectively excited. We also investigate the absorption dependence on the polarization states of designed absorber. The method of engineering the absorption through controlling the temperature and polarization states opens up a new avenue for tunable applications such as data storage and integrated optical circuits.
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Optical microcavities are capable of confining light to a small volume, which could dramatically enhance the light-matter interactions and hence improve the performances of photonic devices. However, in the previous works on the emergent properties with photonic molecules composed of multiple plasmonic microcavities, the underlying physical mechanism is unresolved, thereby imposing an inevitable restriction on manipulating degenerate modes in microcavity with outstanding performance. Here, we demonstrate the mode-mode interaction mechanism in photonic molecules composed of degenerate-mode cavity and single-mode cavity through utilizing the coupled mode theory. Numerical and analytical results further elucidate that the introduction of direct coupling between the degenerate-mode cavity and single-mode cavity can lift the mode degeneracy and give rise to the mode splitting, which contributes to single Fano resonance and dual EIT-like effects in the double-cavity photonic molecule structure. Four times the optical delay time compared to typical double-cavity photonic molecule are achieved after removing the mode degeneracy. Besides, with the preserved mode degeneracy, ultra-wide filtering bandwidth and high peak transmission is obtained in multiple-cavity photonic molecules. Our results provide a broad range of applications for ultra-compact and multifunction photonic devices in highly integrated optical circuits.
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Since 2D materials are typically much more efficient to absorb in-plane polarized light than out-of-plane polarized light, keeping the light polarization in-plane at the 2D material is revealed to be a crucial factor other than critical coupling in light absorption enhancement in a 2D material integrated with a light coupling structure. When the composite of a metal-insulator-metal structure and a 2D material changes from the magnetic resonator form to the metasurface Salisbury screen one, the field polarization at the 2D material changes from a mainly out-of-plane status to a mainly in-plane status. As a result, for graphene, the absorptance enhancement is increased by 1.6 to 4.2 times, the bandwidth enlarged by 3.6 to 6.4 times, and the metal loss suppressed by 7.4 to 24 times in the mid- to far-infrared range, leading to the absorptance of graphene approaching 90% in the mid-infrared regime and 100% in the THz regime. For monolayer black phosphorus, the absorptance enhancement at the wavelength of 3.5 µm is increased by 5.4 times, and the bandwidth enlarged by 1.8 times. For monolayer MoS2, the averaged absorptance in the visible-near infrared range is enhanced by 4.4 times from 15.5% to 68.1%.
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Manipulating polarization, phase, and amplitude simultaneously in real time is an ultimate pursuit of controlling light. Several types of controllable metasurfaces have been realized, but with either low transmission efficiencies or limited control over amplitude, polarization, and phase in real time. Here we present a weak oscillation theory dealing with a new, to the best of our knowledge, type of optical system consisting of many layers of artificial oscillators, with each layer weakly interacting with the external field. As an application of our theory, we demonstrate and simulate a graphene-based metasurface structure to show that the oscillator system could change the focal length by changing the bias voltages. The polarization state to focus can also be selected by the bias voltage. The weak oscillation theory provides a flexible method to control the intensity, phase, and polarization.