scholarly journals Transcending the gain bandwidth limitation in semiconductors for full-colour-tunable lasers

2021 ◽  
Author(s):  
Yi Jiang ◽  
Qi Wei ◽  
King Fai Li ◽  
Mingke Jin ◽  
Hoi Lam Tam ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Semiconductor Lasers ◽  
Visible Region ◽  
Resonance Energy ◽  
Current Gain ◽  
Electromagnetic Spectrum ◽  
Gain Bandwidth ◽  
Lasing Wavelength ◽  
Wide Range ◽  
Bandwidth Limitation

Abstract Developing semiconductors with wide tunable gain bandwidth have always been at the forefront of laser technologies. The variation in feedback resonators can provide a useful tool for producing a relatively wide range of discrete lasing wavelengths. However, the lasing wavelength range is limited by the fundamental gain bandwidth of the single semiconductor itself. Full-colour range lasing through gain bandwidth tuning remains a daunting challenge. Here we demonstrate the feasibility of dynamically tuning amplification/lasing wavelengths in the entire emission spectrum by leveraging on Förster resonance energy transfer (FRET)-assisted guest-host blends. The unprecedented tunability in amplification and lasing is governed by energy transfer process, which enables us to achieve wavelength-tunable semiconductor lasers spanning the full visible region of the electromagnetic spectrum. Our distributed feedback lasers cover almost all CIE colour gamut (94%), which is 170% more perceptible colours than standard Red Green Blue colour space. These insights can guide the versatile and convenient design of semiconductor materials transcending current gain bandwidth limitation, paving the way for next generation of optoelectronic devices.

scholarly journals Methods used to study the oligomeric structure of G-protein-coupled receptors

2017 ◽  
Vol 37 (2) ◽  
Author(s):  
Hui Guo ◽  
Su An ◽  
Richard Ward ◽  
Yang Yang ◽  
Ying Liu ◽  
...  
Keyword(s):  
Energy Transfer ◽  
G Protein ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
G Protein Coupled Receptors ◽  
Experimental Techniques ◽  
Distribution Analysis ◽  
Wide Range ◽  
And Function ◽  
G Protein Coupled

G-protein-coupled receptors (GPCRs), which constitute the largest family of cell surface receptors, were originally thought to function as monomers, but are now recognized as being able to act in a wide range of oligomeric states and indeed, it is known that the oligomerization state of a GPCR can modulate its pharmacology and function. A number of experimental techniques have been devised to study GPCR oligomerization including those based upon traditional biochemistry such as blue-native PAGE (BN-PAGE), co-immunoprecipitation (Co-IP) and protein-fragment complementation assays (PCAs), those based upon resonance energy transfer, FRET, time-resolved FRET (TR-FRET), FRET spectrometry and bioluminescence resonance energy transfer (BRET). Those based upon microscopy such as FRAP, total internal reflection fluorescence microscopy (TIRFM), spatial intensity distribution analysis (SpIDA) and various single molecule imaging techniques. Finally with the solution of a growing number of crystal structures, X-ray crystallography must be acknowledged as an important source of discovery in this field. A different, but in many ways complementary approach to the use of more traditional experimental techniques, are those involving computational methods that possess obvious merit in the study of the dynamics of oligomer formation and function. Here, we summarize the latest developments that have been made in the methods used to study GPCR oligomerization and give an overview of their application.

scholarly journals Versatility of Homogeneous Time-Resolved Fluorescence Resonance Energy Transfer Assays for Biologics Drug Discovery

2014 ◽  
Vol 20 (4) ◽  
pp. 508-518 ◽  
Author(s):  
Christine J. Rossant ◽  
Carl Matthews ◽  
Frances Neal ◽  
Caroline Colley ◽  
Matthew J. Gardener ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Drug Discovery ◽  
Fluorescence Resonance Energy Transfer ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Donor And Acceptor ◽  
Wide Range ◽  
Fluorescence Resonance

Identification of potential lead antibodies in the drug discovery process requires the use of assays that not only measure binding of the antibody to the target molecule but assess a wide range of other characteristics. These include affinity ranking, measurement of their ability to inhibit relevant protein-protein interactions, assessment of their selectivity for the target protein, and determination of their species cross-reactivity profiles to support in vivo studies. Time-resolved fluorescence resonance energy transfer is a technology that offers the flexibility for development of such assays, through the availability of donor and acceptor fluorophore-conjugated reagents for detection of multiple tags or fusion proteins. The time-resolved component of the technology reduces potential assay interference, allowing screening of a range of different crude sample types derived from the bacterial or mammalian cell expression systems often used for antibody discovery projects. Here we describe the successful application of this technology across multiple projects targeting soluble proteins and demonstrate how it has provided key information for the isolation of potential therapeutic antibodies with the desired activity profile.

scholarly journals White Light Emission by Simultaneous One Pot Encapsulation of Dyes into One-Dimensional Channelled Aluminophosphate

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1173
Author(s):  
Rebeca Sola-Llano ◽  
Ainhoa Oliden-Sánchez ◽  
Almudena Alfayate ◽  
Luis Gómez-Hortigüela ◽  
Joaquín Pérez-Pariente ◽  
...  
Keyword(s):  
Energy Transfer ◽  
White Light ◽  
Light Emission ◽  
Resonance Energy ◽  
Fluorescence Decay ◽  
White Light Emission ◽  
Electromagnetic Spectrum ◽  
Transfer Energy ◽  
One Pot ◽  
One Dimensional

By simultaneous occlusion of rationally chosen dyes, emitting in the blue, green and red region of the electromagnetic spectrum, into the one-dimensional channels of a magnesium-aluminophosphate with AEL-zeolitic type structure, MgAPO-11, a solid-state system with efficient white light emission under UV excitation, was achieved. The dyes herein selected—acridine (AC), pyronin Y (PY), and hemicyanine LDS722—ensure overall a good match between their molecular sizes and the MgAPO-11 channel dimensions. The occlusion was carried out via the crystallization inclusion method, in a suitable proportion of the three dyes to render efficient white fluorescence systems by means of fine-tuned FRET (fluorescence resonance energy transfer) energy transfer processes. The FRET processes are thoroughly examined by the analysis of fluorescence decay traces using the femtosecond fluorescence up-conversion technique.

scholarly journals The Fabrication of the Infrared CdSe Doped With Cu Photodetector

2016 ◽  
Vol 8 (3) ◽  
pp. 96
Author(s):  
Hassan H. Mohammed ◽  
Salwan K. J. AL-Ani
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Visible Region ◽  
Film Structure ◽  
Electromagnetic Spectrum ◽  
Wide Range ◽  
Implementation Method ◽  
First Time

In this work, the implementation method of the CdSe doped with Cu (CdSe: Cu) photodetector is presented. This detector is prepared by vacuum evaporation of CdSe films on glass substrate followed by vacuum annealing under an argon atmosphere for doping with copper. This detector is found, for the first time, to cover a wide range of the infrared besides the visible region of the electromagnetic spectrum. This finding of the wavelength tuning is due to the localized energy states of copper atoms inside the band gap of the CdSe. This tuning is compared with recent work in the corresponding colloidal CdSe-ZnS core shell quantum dots and with the quantum well (QWIR) and quantum dots (QDIR) infrared detectors. The major significance of this developed detector is in its synthesis simplicity and its fabrication processes costs in comparison with that of the (QWIR) and (QDIR) detectors. The structural analysis results demonstrated that the vacuum annealing in competition with the doping concentration improves significantly the film structure. Better crystalline structure was reported at 5 wt% of Cu concentration and at annealing temperature of 350 ºC. Besides the measured detectivity at room temperature is D*=2.31×108 cm Hz1/2W-1. This value approaches the detectivity of the state of art mercury cadmium telluride (MCT). This result paves the way for further investigations and improvements.

scholarly journals Plasmon-enhanced Förster energy transfer in Langmuir-Blodgett films based on organic dyes

2019 ◽  
Vol 5 (1) ◽  
pp. 1-6
Author(s):  
Niyazbek Ibrayev ◽  
Evgeniya Seliverstova ◽  
Nazerke Zhumabay
Keyword(s):  
Energy Transfer ◽  
Organic Dyes ◽  
Visible Region ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Maximum Increase ◽  
Förster Energy Transfer ◽  
Langmuir Blodgett Films ◽  
Donor Acceptor ◽  
Silver Island

AbstractThe effect of plasmon resonance of silver island films (SIF) on the interlayer Förster resonance energy transfer (FRET) between xanthene and oxazine dye molecules was studied. It has been shown that the enhancement of FRET can be controlled by changing in the distance between the donor-acceptor system and the SIF. The maximum increase in energy transfer efficiency (EET) by a factor of 2.6 was recorded at a distance of 6 nm from the SIF. The assumption was made that an increase in EET can be associated with both the direct appearance of a plasmon-enhanced rate constant of energy transfer and an increase in the quantum yield of the energy donor in direct contact with the SIF. The results can serve as a basis for studying of photoinduced processes in hybrid materials such as “organic dye-plasmon nanoparticles”, to increase the photosensitivity of solar cells in the visible region of the spectrum, and for the studying of photobiological processes, as well as to create materials with desired properties, sensors and light energy converters.

Efficiency of Solar Cells Based on Natural Dyes with Plasmonic Nanoparticle-Based Photo Anode

2018 ◽  
Vol 18 (06) ◽  
pp. 1850042
Author(s):  
Kirti Sahu ◽  
Mahesh Dhonde ◽  
V. V. S. Murty
Keyword(s):  
Solar Cells ◽  
Visible Region ◽  
Solar Spectrum ◽  
Visible Spectrum ◽  
Natural Dyes ◽  
Maximum Efficiency ◽  
Electromagnetic Spectrum ◽  
Synthetic Dyes ◽  
Vis Spectroscopy ◽  
Wide Range

Cheap and efficient dye sensitized solar cells (DSSCs) can be prepared using natural dyes responding in the visible region of solar spectrum. Localized surface plasmon resonance (LSPR) plays a very important role for the improvement in the efficiency of DSSCs by using Plasmonic nanoparticles (PNPs) for exploiting the visible portion of the solar radiation by transferring the energy from dye to PNP. This energy transfers from dye to semiconductor TiO2 through PNP which increases the overall photo catalytic activity. In the present study, Al-doped TiO2 photoanodes were prepared via sol–gel route and used for DSSC application. Various natural and synthetic dyes are prepared and the optical transmittance and absorbance of the dyes are measured in the wavelength range of 250–850[Formula: see text]nm using UV-Vis spectroscopy and they are used in DSSC. Natural dyes extracted from fruits and synthetic dye based on Ruthenium (Ru) metal complex is used as sensitizers. Power conversion efficiency (PCE) of solar cells utilizing different dyes is compared. Out of the various natural dyes, beetroot and strawberry extracts based dyes show good absorbance in the visible range of electromagnetic spectrum. On the other hand, synthetic dyes based on Ru complex show strong absorbance over a wide range of visible spectrum. The absorbance increases with increase in concentration of Ru in ethanol. The extracts of beetroot, strawberry and mixed fruits show a peak in absorbance spectra at 501nm, 416nm and 332nm, respectively, indicating the absorption over a wide range of visible spectrum. Maximum efficiency of DSSCs utilizing PNPs sensitized with beetroot and strawberry dyes are found to be 1.5% and 1.3%, respectively.

Quantum Dot Bioconjugates as Energy Donors in Fluorescence Resonance Energy Transfer Assays

2003 ◽  
Vol 773 ◽  
Author(s):  
Aaron R. Clapp ◽  
Igor L. Medintz ◽  
J. Matthew Mauro ◽  
Hedi Mattoussi
Keyword(s):  
Energy Transfer ◽  
Quantum Dot ◽  
Organic Dyes ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Genetically Engineered ◽  
Molar Ratio ◽  
Binding Assays ◽  
Specific Sequence ◽  
Donor Acceptor

AbstractLuminescent CdSe-ZnS core-shell quantum dot (QD) bioconjugates were used as energy donors in fluorescent resonance energy transfer (FRET) binding assays. The QDs were coated with saturating amounts of genetically engineered maltose binding protein (MBP) using a noncovalent immobilization process, and Cy3 organic dyes covalently attached at a specific sequence to MBP were used as energy acceptor molecules. Energy transfer efficiency was measured as a function of the MBP-Cy3/QD molar ratio for two different donor fluorescence emissions (different QD core sizes). Apparent donor-acceptor distances were determined from these FRET studies, and the measured distances are consistent with QD-protein conjugate dimensions previously determined from structural studies.

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