ZnxMg60–xO60 Nanoclusters with Tunable Near-Ultraviolet Energy Gaps

2019 ◽  
Author(s):  
Mingyang Chen ◽  
Kangqi Shen ◽  
Govindarajan Saranya ◽  
David A. Dixon
Keyword(s):  
Near Ultraviolet ◽  
Energy Gaps ◽  
Ultraviolet Energy

scholarly journals Thermal and Spectral Sensitivities of Discrete Slow Potentials in Limulus Eye

1968 ◽  
Vol 52 (4) ◽  
pp. 584-599 ◽  
Author(s):  
Alan R. Adolph
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigments ◽  
Light Wavelength ◽  
Slow Potential ◽  
Potential Fluctuations ◽  
Near Ultraviolet ◽  
Irreversible Reduction ◽  
Increasing Temperature ◽  
Ultraviolet Energy ◽  
Time Decrease

The discrete, subthreshold, slow potential fluctuations (SPF's) which can be recorded intracellularly in Limulus ommatidia are sensitive to temperature and light wavelength. SPF frequency increases with increasing temperature (Q10 about 3.5) and light intensity. The effects are additive. SPF rise and decay time decrease with increasing temperature (Q10 between 2 and 3). There is a peak, near 520 nm, in the spectral sensitivity of SPF frequency. This peak may correspond to the wavelength of maximum absorption by rhodopsin in the ommatidia. Hydroxylamine produces a rapid, irreversible reduction of SPF frequency and amplitude perhaps owing to its action on the photopigment. The cornea and crystalline cones fluoresce (peak about 445 nm) when excited by near-ultraviolet energy (380 nm peak) and this fluorescence may influence SPF spectral sensitivity measurements. These findings suggest that the SPF's are the results of photolytic and thermolytic reactions occurring in the ommatidial visual pigments and that they have a role in the mechanisms which transduce light to electrical activity in the visual receptors.

scholarly journals Thermal and Spectral Sensitivities of Discrete Slow Potentials in Limulus Eye

1968 ◽  
Vol 52 (3) ◽  
pp. 584-599 ◽  
Author(s):  
Alan R. Adolph
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigments ◽  
Light Wavelength ◽  
Slow Potential ◽  
Potential Fluctuations ◽  
Near Ultraviolet ◽  
Irreversible Reduction ◽  
Increasing Temperature ◽  
Ultraviolet Energy ◽  
Time Decrease

The discrete, subthreshold, slow potential fluctuations (SPF's) which can be recorded intracellularly in Limulus ommatidia are sensitive to temperature and light wavelength. SPF frequency increases with increasing temperature (Q10 about 3.5) and light intensity. The effects are additive. SPF rise and decay time decrease with increasing temperature (Q10 between 2 and 3). There is a peak, near 520 nm, in the spectral sensitivity of SPF frequency. This peak may correspond to the wavelength of maximum absorption by rhodopsin in the ommatidia. Hydroxylamine produces a rapid, irreversible reduction of SPF frequency and amplitude perhaps owing to its action on the photopigment. The cornea and crystalline cones fluoresce (peak about 445 nm) when excited by near-ultraviolet energy (380 nm peak) and this fluorescence may influence SPF spectral sensitivity measurements. These findings suggest that the SPF's are the results of photolytic and thermolytic reactions occurring in the ommatidial visual pigments and that they have a role in the mechanisms which transduce light to electrical activity in the visual receptors.

A Solvent Free Synthetic Route for Cerium(IV) Metal-Organic Frame-works with UiO-66 Architecture and Their Photocatalytic Application

2019 ◽  
Author(s):  
Matteo Campanelli ◽  
Tiziana Del Giacco ◽  
Filippo De Angelis ◽  
Edoardo Mosconi ◽  
Marco Taddei ◽  
...  
Keyword(s):  
Density Functional ◽  
Chemical Oxidation ◽  
Solvent Free ◽  
Cerium Ammonium Nitrate ◽  
Benzylic Alcohols ◽  
Near Ultraviolet ◽  
Photocatalytic Application ◽  
Activity Density ◽  
Ultraviolet Light Irradiation ◽  
Metal Organic

<div> <p>A novel solvent-free synthesis for Ce-UiO-66 metal-organic frameworks (MOFs) is presented. The MOFs are obtained by simply grinding the reagents, cerium ammonium nitrate (CAN) and the carboxylic linkers, in a mortar for few minutes with the addition of a small amount of acetic acid (AcOH) as modulator (1.75 eq, o.1 ml). The slurry is then transferred into a 1 ml vial and heated at 120°C for 1 day. The MOFs have been characterized for their composition, crystallinity and porosity and employed as heterogenous catalysts for the photo-oxidation reaction of substituted benzylic alcohols to benzaldaldehydes under near ultraviolet light irradiation. The catalytic performances, such as yield, conversion and kinetics, exceed those of similar systems studied by chemical oxidation and using Ce-MOF as catalyst. Moreover, the MOFs were found to be reusable up to three cycles without loss of activity. Density functional theory (DFT) calculations gave an estimation of the band-gap shift due to the different nature of the linkers used and provide useful information on the catalytic activity experimentally observed.</p> </div>

Clustering-Triggered Efficient Room Temperature Phosphorescence from Nonconventional Luminophores

2019 ◽  
Author(s):  
Shuyuan Zheng ◽  
Taiping Hu ◽  
Xin Bin ◽  
Yunzhong Wang ◽  
Yuanping Yi ◽  
...  
Keyword(s):  
Room Temperature ◽  
High Efficiency ◽  
Spin Orbit Coupling ◽  
Design Rationale ◽  
Emission Mechanism ◽  
Room Temperature Phosphorescence ◽  
Electronic Interactions ◽  
Energy Gaps ◽  
Theoretical Results

Pure organic room temperature phosphorescence (RTP) and luminescence from nonconventional luminophores have gained increasing attention. However, it remains challenging to achieve efficient RTP from unorthodox luminophores, on account of the unsophisticated understanding of the emission mechanism. Here we propose a strategy to realize efficient RTP in nonconventional luminophores through incorporation of lone pairs together with clustering and effective electronic interactions. The former promotes spin-orbit coupling and boost the consequent intersystem crossing, whereas the latter narrows energy gaps and stabilizes the triplets, thus synergistically affording remarkable RTP. Experimental and theoretical results of urea and its derivatives verify the design rationale. Remarkably, RTP from thiourea solids with unprecedentedly high efficiency of up to 24.5% is obtained. Further control experiments testify the crucial role of through-space delocalization on the emission. These results would spur the future fabrication of nonconventional phosphors, and moreover should advance understanding of the underlying emission mechanism.<br>

An Infrared Microscope for Use on a Focused Ion Beam for Circuit Edit and Backside Edit Applications

2015 ◽  
Author(s):  
Alexander Richards ◽  
Matthew Weschler ◽  
Michael Durller
Keyword(s):  
Focused Ion Beam ◽  
Near Infrared ◽  
Ion Beam ◽  
Visible Spectrum ◽  
Camera System ◽  
Buried Structures ◽  
Ir Camera ◽  
Area Of Interest ◽  
Near Ultraviolet ◽  
Infrared Microscope

Abstract To help solve the navigational problem, i.e., being able to successfully locate a circuit for probing or editing without destroying chip functionality, a near-infrared (NIR), near-ultraviolet (NUV), and visible spectrum camera system was developed that attaches to most focused ion beam (FIB) or scanning electron microscope vacuum chambers. This paper reviews the details of the design and implementation of the NIR/NUV camera system, as instantiated upon the FEI FIB 200, with a particular focus on its use for the visualization of buried structures, and also for non-destructive real time area of interest location and end point detection. It specifically considers the use of the micro-optical camera system for its benefit in assisting with frontside and backside circuit edit, as well as other typical FIB milling activities. The quality of the image obtained by the IR camera rivals or exceeds traditional optical based imaging microscopy techniques.

scholarly journals MoS2 Based Photodetectors: A Review

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2758
Author(s):  
Alberto Taffelli ◽  
Sandra Dirè ◽  
Alberto Quaranta ◽  
Lucio Pancheri
Keyword(s):  
Electric Fields ◽  
Spectral Range ◽  
Performance Metrics ◽  
Transition Metal Dichalcogenides ◽  
Visible Spectral Range ◽  
Detector Performance ◽  
Strong Light ◽  
Near Ultraviolet ◽  
Passivation Layers ◽  
Low Dimensional

Photodetectors based on transition metal dichalcogenides (TMDs) have been widely reported in the literature and molybdenum disulfide (MoS2) has been the most extensively explored for photodetection applications. The properties of MoS2, such as direct band gap transition in low dimensional structures, strong light–matter interaction and good carrier mobility, combined with the possibility of fabricating thin MoS2 films, have attracted interest for this material in the field of optoelectronics. In this work, MoS2-based photodetectors are reviewed in terms of their main performance metrics, namely responsivity, detectivity, response time and dark current. Although neat MoS2-based detectors already show remarkable characteristics in the visible spectral range, MoS2 can be advantageously coupled with other materials to further improve the detector performance Nanoparticles (NPs) and quantum dots (QDs) have been exploited in combination with MoS2 to boost the response of the devices in the near ultraviolet (NUV) and infrared (IR) spectral range. Moreover, heterostructures with different materials (e.g., other TMDs, Graphene) can speed up the response of the photodetectors through the creation of built-in electric fields and the faster transport of charge carriers. Finally, in order to enhance the stability of the devices, perovskites have been exploited both as passivation layers and as electron reservoirs.

Achieving 17.38% efficiency of ternary organic solar cells enabled by a large-bandgap donor with noncovalent conformational lock

2021 ◽  
Author(s):  
Linyong Xu ◽  
Wuxi Tao ◽  
Heng Liu ◽  
Junhua Ning ◽  
Meihua Huang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Ultraviolet Region ◽  
Near Ultraviolet

A large-bandgap donor BTBR-2F based on noncovalent conformational lock has been designed and synthesized to achieve more complementary absorption with the PM6: Y6 blend in the near-ultraviolet region. The ternary...

A novel near-ultraviolet-light excitable Eu3+-doped Sr2LaTaO6 red phosphor for white-light-emitting diodes

Optik ◽  
2021 ◽  
Vol 240 ◽  
pp. 166908
Author(s):  
Qifeng Tang ◽  
Tao Yang ◽  
Haifeng Huang ◽  
Jinqing Ao ◽  
Biyou Peng ◽  
...  
Keyword(s):  
Ultraviolet Light ◽  
White Light ◽  
Light Emitting Diodes ◽  
Red Phosphor ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
White Light Emitting Diodes
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