scholarly journals Synthesis, optical properties, and amplified spontaneous emission of hybrid Ag–SiO2–CdTe nanocomposite

2017 ◽  
Vol 95 (10) ◽  
pp. 933-940
Author(s):  
A.M. Saad ◽  
M.B. Mohamed ◽  
I.M. Azzouz
Keyword(s):  
Spontaneous Emission ◽  
Amplified Spontaneous Emission ◽  
Silica Shell ◽  
Thermal Therapy ◽  
Threshold Power ◽  
Excitation Wavelength ◽  
Exciton Absorption ◽  
Light Emitting ◽  
Cdte Nanoparticles ◽  
And Control

In this work, a hybrid nanocomposite of metal–dielectric–semiconductor, Ag–SiO2–CdTe, nanoparticles has been synthesized. Silica shell was used as a spacer to isolate and control the distance between Ag plasmonic and luminescent CdTe QDs. It was found that insertion of silica shell enhances the plasmonic field more than 31%. Accordingly, Ag-SiO2 plasmonic enhances the luminescence and quantum yield of CdTe quantum dots by 200% and 55%, respectively. The threshold power of amplified spontaneous emission of CdTe was found to depend on both temperature and excitation wavelength location with respect to plasmon and exciton absorption. This nanocomposite could be potentially used in light-emitting diodes, biological sensing, and thermal therapy.

scholarly journals Amplified Spontaneous Emission and Optical Gain in Organic Single Crystal Quinquethiophene

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 609 ◽  
Author(s):  
Muhammad Zeb ◽  
Muhammad Tahir ◽  
Fida Muhammad ◽  
Suhana Mohd Said ◽  
Mohd Faizul Mohd Sabri ◽  
...  
Keyword(s):  
Single Crystal ◽  
Spontaneous Emission ◽  
Threshold Energy ◽  
Pump Energy ◽  
Optical Gain ◽  
Amplified Spontaneous Emission ◽  
Stimulated Emission ◽  
Excitation Wavelength ◽  
Optical Amplification ◽  
Organic Single Crystal

In this paper, we report optical characteristics of an organic single crystal oligomer 5,5⁗-diphenyl-2,2′:5′,2″:5″,2‴:5‴,2⁗-quinquethiophene (P5T). P5T crystal is a thiophene/phenylene co-oligomer that possesses better charge mobility as well as photoluminescence quantum efficiency (PLQE) as compared to other organic materials. Stimulated emission in P5T is investigated via amplified spontaneous emission (ASE) measurements within broad pump energies ranging from 35.26 to 163.34 µJ/cm2. An Nd-YAG femtosecond-tunable pulsed laser is used as a pump energy source for the ASE measurements of P5T crystals at an excitation wavelength of 445 nm. The ASE spectra exhibit optical amplification in P5T crystals at a 625 nm peak wavelength with a lower threshold energy density (Eth) ≈ 52.64 μJ/cm2. P5T also demonstrates higher optical gain with a value of 72 cm−1, that is calculated by using the variable stripe-length method. The value of PLQE is measured to be 68.24% for P5T. This study proposes potential applications of P5T single crystals in organic solid state lasers, photodetectors, and optical amplifiers.

scholarly journals Broadened Bandwidth Amplified Spontaneous Emission from Blue GaN-Based Short-Cavity Superluminescent Light-Emitting Diodes

2020 ◽  
Vol 9 (1) ◽  
pp. 015019 ◽  
Author(s):  
Hezhi Zhang ◽  
Ching-Wen Shih ◽  
Denis Martin ◽  
Alexander Caut ◽  
Jean-François Carlin ◽  
...  
Keyword(s):  
Spontaneous Emission ◽  
Light Emitting Diodes ◽  
Amplified Spontaneous Emission ◽  
Light Emitting

scholarly journals Light Emission Properties of Thermally Evaporated CH3NH3PbBr3 Perovskite from Nano- to Macro-Scale: Role of Free and Localized Excitons

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 211
Author(s):  
Claudia Triolo ◽  
Maria Luisa De Giorgi ◽  
Antonella Lorusso ◽  
Arianna Cretì ◽  
Saveria Santangelo ◽  
...  
Keyword(s):  
Spontaneous Emission ◽  
Light Emission ◽  
Amplified Spontaneous Emission ◽  
Stimulated Emission ◽  
Thin Layers ◽  
Light Emitting ◽  
Macro Scale ◽  
Localized Excitons ◽  
Emitting Species

Over the past decade, interest about metal halide perovskites has rapidly increased, as they can find wide application in optoelectronic devices. Nevertheless, although thermal evaporation is crucial for the development and engineering of such devices based on multilayer structures, the optical properties of thermally deposited perovskite layers (spontaneous and amplified spontaneous emission) have been poorly investigated. This paper is a study from a nano- to micro- and macro-scale about the role of light-emitting species (namely free carriers and excitons) and trap states in the spontaneous emission of thermally evaporated thin layers of CH3NH3PbBr3 perovskite after wet air UV light trap passivation. The map of light emission from grains, carried out by SNOM at the nanoscale and by micro-PL techniques, clearly indicates that free and localized excitons (EXs) are the dominant light-emitting species, the localized excitons being the dominant ones in the presence of crystallites. These species also have a key role in the amplified spontaneous emission (ASE) process: for higher excitation densities, the relative contribution of localized EXs basically remains constant, while a clear competition between ASE and free EXs spontaneous emission is present, which suggests that ASE is due to stimulated emission from the free EXs.

Revealing long–range orbit–orbit interaction between coherent light-emitting excitons occurring in amplified spontaneous emission in CsPbBr3 microstructures

2021 ◽  
Author(s):  
Miaosheng Wang ◽  
Jia Zhang ◽  
Xixiang Zhu ◽  
Hengxing Xu ◽  
Bin Hu
Keyword(s):  
Long Range ◽  
Spontaneous Emission ◽  
Amplified Spontaneous Emission ◽  
Orbit Interaction ◽  
Coherent Light ◽  
Light Emitting

This paper reports a new phenomenon that long–range orbit–orbit interaction is established through orbital polarizations between coherent light-emitting excitons during the generation of amplified spontaneous emission in CsPbBr3 microrods.

scholarly journals Amplified spontaneous emission and gain in highly concentrated Rhodamine-doped peptide derivative

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrey Machnev ◽  
Daniel Ofer ◽  
Ivan Shishkin ◽  
Vitali Kozlov ◽  
Carlo Diaferia ◽  
...  
Keyword(s):  
Spontaneous Emission ◽  
Rhodamine B ◽  
Fluorescent Dyes ◽  
Amplified Spontaneous Emission ◽  
Concentration Quenching ◽  
Hybrid Polymer ◽  
High Quantum Yield ◽  
Light Emitting ◽  
Peptide Derivative ◽  
Living Organisms

AbstractBioinspired fluorescence, being widely explored for imaging purposes, faces challenges in delivering bright biocompatible sources. While quite a few techniques have been developed to reach this goal, encapsulation of high-quantum yield fluorescent dyes in natural biological forms suggest achieving superior light-emitting characteristics, approaching amplified spontaneous emission and even lasing. Here we compare gain capabilities of highly concentrated Rhodamine B solutions with a newly synthesized biocompatible peptide derivative hybrid polymer/peptide material, RhoB-PEG1300-F6, which contains the fluorescent covalently bound dye. While concentration quenching effects limit the maximal achievable gain of dissolved Rhodamine B, biocompatible conjugation allows elevating amplification coefficients towards moderately high values. In particular, Rhodamine B, anchored to the peptide derivative material, demonstrates gain of 22–23 cm−1 for a 10−2 M solution, while a pure dye solution possesses 25% smaller values at the same concentration. New biocompatible fluorescent agents pave ways to demonstrate lasing in living organisms and can be further introduced to therapeutic applications, if proper solvents are found.

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