scholarly journals High-performance photodetector based on an interface engineering-assisted graphene/silicon Schottky junction

2022 ◽  
Vol 8 (1) ◽  
Author(s):  
Peirui Ji ◽  
Shuming Yang ◽  
Yu Wang ◽  
Kaili Li ◽  
Yiming Wang ◽  
...  
Keyword(s):  
Dark Current ◽  
High Performance ◽  
Near Infrared ◽  
Environmental Stability ◽  
Infrared Light ◽  
Broadband Absorption ◽  
Operation Speed ◽  
Novel Structure ◽  
Wide Range ◽  
Iron Garnet

AbstractGraphene/silicon Schottky junctions have been proven efficient for photodetection, but the existing high dark current seriously restricts applications such as weak signal detection. In this paper, a thin layer of gadolinium iron garnet (Gd3Fe5O12, GdIG) film is introduced to engineer the interface of a graphene/silicon Schottky photodetector. The novel structure shows a significant decrease in dark current by 54 times at a −2 V bias. It also exhibits high performance in a self-powered mode in terms of an Ilight/Idark ratio up to 8.2 × 106 and a specific detectivity of 1.35 × 1013 Jones at 633 nm, showing appealing potential for weak-light detection. Practical suitability characterizations reveal a broadband absorption covering ultraviolet to near-infrared light and a large linear response with a wide range of light intensities. The device holds an operation speed of 0.15 ms, a stable response for 500 continuous working cycles, and long-term environmental stability after several months. Theoretical analysis shows that the interlayer increases the barrier height and passivates the contact surface so that the dark current is suppressed. This work demonstrates the good capacity of GdIG thin films as interlayer materials and provides a new solution for high-performance photodetectors.

An ordered copper nanowell-array film with near-perfect broadband absorption from ultraviolet to near-infrared light

2020 ◽  
Vol 59 (11) ◽  
pp. 110906
Author(s):  
Juan Shen ◽  
Yong Ren ◽  
Xinxin Zhu ◽  
Min Mao ◽  
Quan Zhou ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Broadband Absorption

High-performance WO3−x-WSe2/SiO2/n-Si heterojunction near-infrared photodetector via a homo-doping strategy

2018 ◽  
Vol 6 (21) ◽  
pp. 5821-5829 ◽  
Author(s):  
Tianchao Guo ◽  
Cuicui Ling ◽  
Teng Zhang ◽  
Hui Li ◽  
Xiaofang Li ◽  
...  
Keyword(s):  
Barrier Height ◽  
Dark Current ◽  
High Performance ◽  
Near Infrared ◽  
Infrared Photodetector ◽  
Interface Barrier

The enhanced performance of WO3−x-WSe2/SiO2/n-Si can be mainly attributed to the down-shift of the EF of WO3−x-WSe2, which results in a larger interface barrier height and a greatly reduced dark current.

scholarly journals Synthesis of high-performance magnetic garnet materials and garnet-bismuth oxide nanocomposites using physical vapor deposition followed by high-temperature crystallization

2011 ◽  
Vol 83 (11) ◽  
pp. 1971-1980 ◽  
Author(s):  
Mohammad Nur-E-Alam ◽  
Mikhail Vasiliev ◽  
Kamal Alameh ◽  
Viacheslav Kotov
Keyword(s):  
High Temperature ◽  
Optical Sensors ◽  
Physical Vapor Deposition ◽  
High Performance ◽  
Near Infrared ◽  
Rf Sputtering ◽  
Nanocomposite Films ◽  
Sputtering Deposition ◽  
Garnet Phase ◽  
Iron Garnet

Bi-substituted iron garnet (Bi:IG) compounds synthesized in thin film form are the best semi-transparent magneto-optical (MO) materials for applications in magnetic recording, optical sensors, and photonics. These materials can possess attractive magnetic properties and the highest specific Faraday rotation in the visible and near-infrared spectral regions, if the deposited layers contain a high volumetric fraction of the garnet phase and possess high-quality surfaces and microstructure. In this paper, we study the effects of various deposition and annealing process parameters on the properties of Bi:IG and garnet-oxide nanocomposite films of several composition types fabricated using radio-frequency (RF) sputtering deposition followed by high-temperature isothermal crystallization. We also investigate the kinetics of garnet phase formation within a garnet-Bi-oxide nanocomposite material.

Absorption and Scatter Corrections for Transflectance Measurements in Nonhomogeneous Fiber Samples

1998 ◽  
Vol 6 (A) ◽  
pp. A35-A44 ◽  
Author(s):  
R.A. Taylor
Keyword(s):  
High Speed ◽  
Near Infrared ◽  
Light Transmission ◽  
Accurate Determination ◽  
Fiber Optic Sensor ◽  
Infrared Light ◽  
Specimen Preparation ◽  
Absorption Bands ◽  
Speed Sensor ◽  
Wide Range

A new fiber optic sensor was developed to measure the mass of optically thin cotton samples by integrating light transmission and reflectance signals. High speed measurements of cotton strength requires an accurate determination of the specimen mass without use of laborious cut-and-weigh methods. A previous high speed sensor measured changes in visible light transmission which required secondary measurements of fiber fineness to adjust the data for light scattering. Fiber orientation also affected scattering which required a precise control on specimen preparation. The new sensor measures fiber specimen transflectance using near infrared light. Because cellulose (the basic compound in cotton) exhibits strong absorption bands, its concentration can be accurately measured using near infrared absorbance. In this report we show that an integratinq sensor gave the best measurement of cotton fiber mass. Additionally, we demonstrated its accuracy over a wide range of fiber orientations using a novel fiber specimen tension experiment.

scholarly journals Age-related changes in diffuse optical tomography sensitivity profiles in infancy

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252036
Author(s):  
Xiaoxue Fu ◽  
John E. Richards
Keyword(s):  
Near Infrared ◽  
Optical Tomography ◽  
Diffuse Optical Tomography ◽  
Hemoglobin Concentration ◽  
Separation Distance ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Photon Propagation ◽  
Age Related ◽  
Wide Range

Diffuse optical tomography uses near-infrared light spectroscopy to measure changes in cerebral hemoglobin concentration. Anatomical interpretations of the location that generates the hemodynamic signal requires accurate descriptions of diffuse optical tomography sensitivity to the underlying cortical structures. Such information is limited for pediatric populations because they undergo rapid head and brain development. The present study used photon propagation simulation methods to examine diffuse optical tomography sensitivity profiles in realistic head models among infants ranging from 2 weeks to 24 months with narrow age bins, children (4 and 12 years) and adults (20 to 24 years). The sensitivity profiles changed systematically with the source-detector separation distance. The peak of the sensitivity function in the head was largest at the smallest separation distance and decreased as separation distance increased. The fluence value dissipated more quickly with sampling depth at the shorter source-detector separations than the longer separation distances. There were age-related differences in the shape and variance of sensitivity profiles across a wide range of source-detector separation distances. Our findings have important implications in the design of sensor placement and diffuse optical tomography image reconstruction in (functional) near-infrared light spectroscopy research. Age-appropriate realistic head models should be used to provide anatomical guidance for standalone near-infrared light spectroscopy data in infants.

scholarly journals Photothermal Polymer Nanocomposites of Tungsten Bronze Nanorods with Enhanced Tensile Elongation at Low Filler Contents

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1740 ◽  
Author(s):  
Byoungyun Jeon ◽  
Taehyung Kim ◽  
Dabin Lee ◽  
Tae Joo Shin ◽  
Kyung Wha Oh ◽  
...  
Keyword(s):  
Polymer Nanocomposites ◽  
Near Infrared ◽  
Tensile Elongation ◽  
Tungsten Bronze ◽  
Heat Emission ◽  
Cold Weather ◽  
Infrared Light ◽  
Droplet Transport ◽  
Wide Range ◽  
Weather Resistance

We present polymer nanocomposites of tungsten bronze nanorods (TBNRs) and ethylene propylene diene monomers (EPDM). The combination of these components allows the simultaneous enhancement in the mechanical and photothermal properties of the composites at low filler contents. The as-synthesized TBNRs had lengths and diameters of 14.0 ± 2.4 nm and 2.5 ± 0.5 nm, respectively, and were capped with oleylamine, which has a chemical structure similar to EPDM, making the TBNRs compatible with the bulk EPDM matrix. The TBNRs absorb a wide range of near-infrared light because of the sub-band transitions induced by alkali metal doping. Thus, the nanocomposites of TBNRs in EPDM showed enhanced photothermal properties owing to the light absorption and subsequent heat emission by the TBNRs. Noticeably, the nanocomposite with only 3 wt% TBNRs presented significantly enhanced tensile strain at break, in comparison with those of pristine EPDM, nanocomposites with 1 and 2 wt % TBNRs, and those with tungsten bronze nanoparticles, because of the alignment of the nanorods during tensile elongation. The photothermal and mechanical properties of these nanocomposites make them promising materials for various applications such as in fibers, foams, clothes with cold weather resistance, patches or mask-like films for efficient transdermal delivery upon heat generation, and photoresponsive surfaces for droplet transport by the thermocapillary effect in microfluidic devices and microengines.

scholarly journals Hybrid Nanodisk Film for Ultra-Narrowband Filtering, Near-Perfect Absorption and Wide Range Sensing

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 334 ◽  
Author(s):  
Wenli Cui ◽  
Wei Peng ◽  
Li Yu ◽  
Xiaolin Luo ◽  
Huixuan Gao ◽  
...  
Keyword(s):  
Plasmon Resonance ◽  
High Performance ◽  
Near Infrared ◽  
Structural Parameters ◽  
Normal Incidence ◽  
Plasmonic Nanostructures ◽  
Perfect Absorption ◽  
Biomedical Sensing ◽  
Wide Range ◽  
Plasmon Resonances

The miniaturization and integration of photonic devices are new requirements in the novel optics field due to the development of photonic information technology. In this paper, we report that a multifunctional layered structure of Au, SiO2 and hexagonal nanodisk film is advantageous for ultra-narrowband filtering, near-perfect absorption and sensing in a wide refractive index (RI) region. This hexagonal nanostructure presented two remarkable polarization independent plasmon resonances with near-zero reflectivity and near-perfect absorptivity under normal incidence in the visible and near-infrared spectral ranges. The narrowest full width at half maximum (FWHM) of these resonances was predicted to be excellent at 5 nm. More notably, the double plasmon resonances showed extremely obvious differences in RI responses. For the first plasmon resonance, an evident linear redshift was observed in a wide RI range from 1.00 to 1.40, and a high RI sensitivity of 600 nm/RIU was obtained compared to other plasmonic nanostructures, such as square and honeycomb-like nanostructures. For the second plasmon resonance with excellent FWHM at 946 nm, its wavelength position almost remained unmovable in the case of changing RI surrounding nanodisks in the same regime. Most unusually, its resonant wavelength was insensitive to nearly all structural parameters except the structural period. The underlying physical mechanism was analyzed in detail for double plasmon resonances. This work was significant in developing high-performance integrated optical devices for filtering, absorbing and biomedical sensing.

scholarly journals Biomedical optical properties of color light and near-infrared fluorescence separated-merged imager

2019 ◽  
Vol 12 (06) ◽  
pp. 1940001
Author(s):  
Rui Zhang ◽  
Ya-Zhou Xue ◽  
Xiao-Feng Yang
Keyword(s):  
Optical Properties ◽  
Near Infrared ◽  
Perioperative Period ◽  
Infrared Light ◽  
Agarose Gel ◽  
Near Infrared Fluorescence ◽  
Imaging Characteristics ◽  
Reflected Light ◽  
Wide Range

Objective: We study the biomedical optical properties of the color light and near-infrared fluorescence separated-merged imager. Materials and Methods: The color light and near-infrared fluorescence separated-merged imager can illuminate the visible light and the near-infrared light of [Formula: see text][Formula: see text]nm, receiving the reflected light and [Formula: see text][Formula: see text]nm near-infrared fluorescence, and display the color, fluorescence and merge image. ICG solution of different concentration, including standing time, was allocated to study the best imaging condition in vitro, and the depth of fluorescence penetration was studied with 5% agarose gel; the imaging characteristics of the imager was studied using SD rat; and then the SLNs tracing in 4 cases of penile carcinoma was performed. Results: When the concentration of ICG is 13.11[Formula: see text][Formula: see text]mol/L, the fluorescence intensity and the merge image are the best. The maximum depth of fluorescence imaging is 9[Formula: see text]mm in 5% agarose gel, while the bone has the greatest influence on it. The SLNs tracing shows that the imager can locate the SLNs in vitro, to achieve perioperative navigation during biopsy. Conclusion: There are many factors that affect the imaging effect, but the imaging effect of the imager meets the requirement of vision in a wide range, and can effectively trace the SLNs in perioperative period.

scholarly journals Lipophilicity of Bacteriochlorin-Based Photosensitizers as a Determinant for PDT Optimization through the Modulation of the Inflammatory Mediators

2019 ◽  
Vol 9 (1) ◽  
pp. 8 ◽  
Author(s):  
Barbara Pucelik ◽  
Luis G. Arnaut ◽  
Janusz M. Dąbrowski
Keyword(s):  
Immune Response ◽  
Molecular Mechanisms ◽  
Near Infrared ◽  
Antitumor Immune Response ◽  
Infrared Light ◽  
Gm Csf ◽  
Hydrophobic Compound ◽  
Tnf Α ◽  
Wide Range

Photodynamic therapy (PDT) augments the host antitumor immune response, but the role of the PDT effect on the tumor microenvironment in dependence on the type of photosensitizer and/or therapeutic protocols has not been clearly elucidated. We employed three bacteriochlorins (F2BOH, F2BMet and Cl2BHep) of different polarity that absorb near-infrared light (NIR) and generated a large amount of reactive oxygen species (ROS) to compare the PDT efficacy after various drug-to-light intervals: 15 min. (V-PDT), 3h (E-PDT) and 72h (C-PDT). We also performed the analysis of the molecular mechanisms of PDT crucial for the generation of the long-lasting antitumor immune response. PDT-induced damage affected the integrity of the host tissue and developed acute (protocol-dependent) local inflammation, which in turn led to the infiltration of neutrophils and macrophages. In order to further confirm this hypothesis, a number of proteins in the plasma of PDT-treated mice were identified. Among a wide range of cytokines (IL-6, IL-10, IL-13, IL-15, TNF-α, GM-CSF), chemokines (KC, MCP-1, MIP1α, MIP1β, MIP2) and growth factors (VEGF) released after PDT, an important role was assigned to IL-6. PDT protocols optimized for studied bacteriochlorins led to a significant increase in the survival rate of BALB/c mice bearing CT26 tumors, but each photosensitizer (PS) was more or less potent, depending on the applied DLI (15 min, 3 h or 72 h). Hydrophilic (F2BOH) and amphiphilic (F2BMet) PSs were equally effective in V-PDT (>80 cure rate). F2BMet was the most efficient in E-PDT (DLI = 3h), leading to a cure of 65 % of the animals. Finally, the most powerful PS in the C-PDT (DLI = 72 h) regimen turned out to be the most hydrophobic compound (Cl2BHep), allowing 100 % of treated animals to be cured at a light dose of only 45 J/cm2.

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