Tuning Optical Absorption and Emission of Sub-Nanometer Gold-Caged Metal Systems M@Au14 by Substitutional Doping

Gao, Bulusu and Zeng have recently reported a new series of isoelectronic, sub-nanometer gold-caged metal systems M@Au14 which have large energy gaps than icosahedral W@Au12 and Au32 and tetrahedral Au20. In this communication, we propose a "tuning" scheme, substitutional-doping, to achieve the tunable optical excitation and emission of M@Au14 over a broad wavelength region. For example, the optical absorption gaps of isoelectronic M@Au14 could be tuned from the near infrared to green by substituting the metal M with group IIIB, IVB, and VB constituents in the periodic table. Our results provide basic guidelines for further experimental studies on the spectral properties of M@Au14 as well as for the development of M@Au14-based tunable optoelectronic devices.

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Near-Infrared Emissions of Sm3+ in Li2O-K2O-BaO-PbO-Bi2O3-Ga2O3 Glasses

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.476-478.1121 ◽

2012 ◽

Vol 476-478 ◽

pp. 1121-1124 ◽

Cited By ~ 2

Author(s):

Xiang Ling Zhang ◽

Ming Liu ◽

Xin Zhao ◽

Hai Lin

Keyword(s):

Cross Sections ◽

Near Infrared ◽

Transition Probabilities ◽

Optoelectronic Devices ◽

Wavelength Region ◽

Stimulated Emission ◽

Low Loss ◽

Spontaneous Transition ◽

Potential Applications ◽

Transmission Window

μNear-infrared (NIR) emissions have been observed in Sm3+doped low phonon energy heavy-metal-gallate glasses. The full-widths at half-maximum (FWHMs) of three fluorescence bands peaking at 960, 1038, and 1185 nm were derived to be 31, 36, and 42 nm, respectively, and the spontaneous transition probabilities were calculated to be 66, 16, and 6 s-1. Maximum stimulated emission cross-sections ( σem) for NIR transition emissions were obtained to be 4.22´10-22, 1.37´10-22, and 0.71´10-22cm2, respectively. Investigations on multi-channel NIR transition emissions of Sm3+, especially on the ~1.19 μm emission, which lies in the low-loss wavelength region of transmission window, are beneficial for potential applications in infrared optoelectronic devices.

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Creation of Negatively Charged Boron Vacancies in Hexagonal Boron Nitride Crystal by Electron Irradiation and Mechanism of Inhomogeneous Broadening of Boron Vacancy-Related Spin Resonance Lines

Nanomaterials ◽

10.3390/nano11061373 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1373

Author(s):

Fadis F. Murzakhanov ◽

Boris V. Yavkin ◽

Georgiy V. Mamin ◽

Sergei B. Orlinskii ◽

Ivan E. Mumdzhi ◽

...

Keyword(s):

Boron Nitride ◽

Electron Irradiation ◽

Near Infrared ◽

Hexagonal Boron Nitride ◽

Optical Excitation ◽

High Energy ◽

Infrared Range ◽

Zero Field ◽

Zero Field Splitting ◽

Spin Resonance

Optically addressable high-spin states (S ≥ 1) of defects in semiconductors are the basis for the development of solid-state quantum technologies. Recently, one such defect has been found in hexagonal boron nitride (hBN) and identified as a negatively charged boron vacancy (VB−). To explore and utilize the properties of this defect, one needs to design a robust way for its creation in an hBN crystal. We investigate the possibility of creating VB− centers in an hBN single crystal by means of irradiation with a high-energy (E = 2 MeV) electron flux. Optical excitation of the irradiated sample induces fluorescence in the near-infrared range together with the electron spin resonance (ESR) spectrum of the triplet centers with a zero-field splitting value of D = 3.6 GHz, manifesting an optically induced population inversion of the ground state spin sublevels. These observations are the signatures of the VB− centers and demonstrate that electron irradiation can be reliably used to create these centers in hBN. Exploration of the VB− spin resonance line shape allowed us to establish the source of the line broadening, which occurs due to the slight deviation in orientation of the two-dimensional B-N atomic plains being exactly parallel relative to each other. The results of the analysis of the broadening mechanism can be used for the crystalline quality control of the 2D materials, using the VB− spin embedded in the hBN as a probe.

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Metalorganic chemical vapor deposition of InN quantum dots and nanostructures

Light Science & Applications ◽

10.1038/s41377-021-00593-8 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Caroline E. Reilly ◽

Stacia Keller ◽

Shuji Nakamura ◽

Steven P. DenBaars

Keyword(s):

Quantum Dots ◽

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Metalorganic Chemical Vapor Deposition ◽

Near Infrared ◽

Optoelectronic Devices ◽

Chemical Vapor ◽

Electromagnetic Spectrum ◽

Material System ◽

Metalorganic Chemical

AbstractUsing one material system from the near infrared into the ultraviolet is an attractive goal, and may be achieved with (In,Al,Ga)N. This III-N material system, famous for enabling blue and white solid-state lighting, has been pushing towards longer wavelengths in more recent years. With a bandgap of about 0.7 eV, InN can emit light in the near infrared, potentially overlapping with the part of the electromagnetic spectrum currently dominated by III-As and III-P technology. As has been the case in these other III–V material systems, nanostructures such as quantum dots and quantum dashes provide additional benefits towards optoelectronic devices. In the case of InN, these nanostructures have been in the development stage for some time, with more recent developments allowing for InN quantum dots and dashes to be incorporated into larger device structures. This review will detail the current state of metalorganic chemical vapor deposition of InN nanostructures, focusing on how precursor choices, crystallographic orientation, and other growth parameters affect the deposition. The optical properties of InN nanostructures will also be assessed, with an eye towards the fabrication of optoelectronic devices such as light-emitting diodes, laser diodes, and photodetectors.

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High performing flexible optoelectronic devices using thin films of topological insulator

Scientific Reports ◽

10.1038/s41598-020-80738-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Animesh Pandey ◽

Reena Yadav ◽

Mandeep Kaur ◽

Preetam Singh ◽

Anurag Gupta ◽

...

Keyword(s):

Thin Films ◽

Optical Properties ◽

Nonlinear Optical ◽

Near Infrared ◽

Optoelectronic Devices ◽

Nonlinear Optical Properties ◽

Metallic Surface ◽

Strong Light ◽

High Performing ◽

Decay Times

AbstractTopological insulators (TIs) possess exciting nonlinear optical properties due to presence of metallic surface states with the Dirac fermions and are predicted as a promising material for broadspectral phodotection ranging from UV (ultraviolet) to deep IR (infrared) or terahertz range. The recent experimental reports demonstrating nonlinear optical properties are mostly carried out on non-flexible substrates and there is a huge demand for the fabrication of high performing flexible optoelectronic devices using new exotic materials due to their potential applications in wearable devices, communications, sensors, imaging etc. Here first time we integrate the thin films of TIs (Bi2Te3) with the flexible PET (polyethylene terephthalate) substrate and report the strong light absorption properties in these devices. Owing to small band gap material, evolving bulk and gapless surface state conduction, we observe high responsivity and detectivity at NIR (near infrared) wavelengths (39 A/W, 6.1 × 108 Jones for 1064 nm and 58 A/W, 6.1 × 108 Jones for 1550 nm). TIs based flexible devices show that photocurrent is linearly dependent on the incident laser power and applied bias voltage. Devices also show very fast response and decay times. Thus we believe that the superior optoelectronic properties reported here pave the way for making TIs based flexible optoelectronic devices.

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Optical Absorption Spectroscopy of DNA-Wrapped HiPco Carbon Nanotubes

Materials Science Forum ◽

10.4028/www.scientific.net/msf.943.95 ◽

2019 ◽

Vol 943 ◽

pp. 95-99

Author(s):

Li Jun Wang ◽

Kazuo Umemura

Keyword(s):

Carbon Nanotubes ◽

Aqueous Solution ◽

Optical Absorption ◽

Absorption Spectroscopy ◽

Near Infrared ◽

Nir Spectroscopy ◽

Optical Characterization ◽

Optical Absorption Spectroscopy ◽

Double Stranded Dna

Optical absorption spectroscopy provides evidence for individually dispersed carbon nanotubes. A common method to disperse SWCNTs into aqueous solution is to sonicate the mixture in the presence of a double-stranded DNA (dsDNA). In this paper, optical characterization of dsDNA-wrapped HiPco carbon nanotubes (dsDNA-SWCNT) was carried out using near infrared (NIR) spectroscopy and photoluminescence (PL) experiments. The findings suggest that SWCNT dispersion is very good in the environment of DNA existing. Additionally, its dispersion depends on dsDNA concentration.

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Satellite monitoring of different vegetation types by differential optical absorption spectroscopy (DOAS) in the red spectral range

Atmospheric Chemistry and Physics ◽

10.5194/acp-7-69-2007 ◽

2007 ◽

Vol 7 (1) ◽

pp. 69-79 ◽

Cited By ~ 20

Author(s):

T. Wagner ◽

S. Beirle ◽

T. Deutschmann ◽

M. Grzegorski ◽

U. Platt

Keyword(s):

Optical Absorption ◽

Absorption Spectroscopy ◽

Spectral Range ◽

Near Infrared ◽

Vegetation Type ◽

Differential Optical Absorption Spectroscopy ◽

Trace Gas ◽

Satellite Monitoring ◽

Optical Absorption Spectroscopy ◽

Vegetation Types

Abstract. A new method for the satellite remote sensing of different types of vegetation and ocean colour is presented. In contrast to existing algorithms relying on the strong change of the reflectivity in the red and near infrared spectral region, our method analyses weak narrow-band (few nm) reflectance structures (i.e. "fingerprint" structures) of vegetation in the red spectral range. It is based on differential optical absorption spectroscopy (DOAS), which is usually applied for the analysis of atmospheric trace gas absorptions. Since the spectra of atmospheric absorption and vegetation reflectance are simultaneously included in the analysis, the effects of atmospheric absorptions are automatically corrected (in contrast to other algorithms). The inclusion of the vegetation spectra also significantly improves the results of the trace gas retrieval. The global maps of the results illustrate the seasonal cycles of different vegetation types. In addition to the vegetation distribution on land, they also show patterns of biological activity in the oceans. Our results indicate that improved sets of vegetation spectra might lead to more accurate and more specific identification of vegetation type in the future.

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A phthalocyanine-based fluorescent sensor for Zn2+ ion

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424612501374 ◽

2013 ◽

Vol 17 (01n02) ◽

pp. 99-103 ◽

Cited By ~ 8

Author(s):

Hui He ◽

Jian-Yong Liu ◽

Dennis K.P. Ng

Keyword(s):

Metal Ions ◽

Spectral Properties ◽

Fluorescence Spectra ◽

Near Infrared ◽

Fluorescent Sensor ◽

High Sensitivity ◽

Absorption And Fluorescence Spectra

This paper describes the preparation and spectral properties of a near-infrared fluorophore in which two bis(2-picolyl)amino moieties are axially linked to a silicon(IV) phthalocyanine core. The effects of various metal ions on its absorption and fluorescence spectra have been examined. The results indicate that this compound shows a high sensitivity and moderate selectivity toward Zn2+ ion.

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Novel Two-Dimensional Layered MoSi2Z4 (Z = P, As): New Promising Optoelectronic Materials

Nanomaterials ◽

10.3390/nano11030559 ◽

2021 ◽

Vol 11 (3) ◽

pp. 559

Author(s):

Hui Yao ◽

Chao Zhang ◽

Qiang Wang ◽

Jianwei Li ◽

Yunjin Yu ◽

...

Keyword(s):

Optical Absorption ◽

Incident Light ◽

Optoelectronic Devices ◽

Large Family ◽

Middle Layer ◽

Optoelectronic Device ◽

First Principles Calculation ◽

Polarization Angle ◽

Two Dimensional ◽

Conducting Materials

Very recently, two new two-dimensional (2D) layered semi-conducting materials MoSi2N4 and WSi2N4 were successfully synthesized in experiments, and a large family of these two 2D materials, namely MA2Z4, was also predicted theoretically (Science, 369, 670 (2020)). Motivated by this exciting family, in this work, we systematically investigate the mechanical, electronic and optical properties of monolayer and bilayer MoSi2P4 and MoSi2As4 by using the first-principles calculation method. Numerical results indicate that both monolayer and bilayer MoSi2Z4 (Z = P, As) present good structural stability, isotropic mechanical parameters, moderate bandgap, favorable carrier mobilities, remarkable optical absorption, superior photon responsivity and external quantum efficiency. Especially, due to the wave-functions of band edges dominated by d orbital of the middle-layer Mo atoms are screened effectively, the bandgap and optical absorption hardly depend on the number of layers, providing an added convenience in the experimental fabrication of few-layer MoSi2Z4-based electronic and optoelectronic devices. We also build a monolayer MoSi2Z4-based 2D optoelectronic device, and quantitatively evaluate the photocurrent as a function of energy and polarization angle of the incident light. Our investigation verifies the excellent performance of a few-layer MoSi2Z4 and expands their potential application in nanoscale electronic and optoelectronic devices.

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