Investigations of structural and optical properties of Bi2−xCrxS3 nanocrystals embedded in host glass

Guimarães, Éder V.; Mikhail, H.; Silva, Anielle Christine Almeida; Dantas, Noélio O.; Silva, Ricardo Siqueira da

doi:10.1016/j.matlet.2020.127430

Cited by 13 publications

(11 citation statements)

References 68 publications

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“…This orbital coupling modifies the optical properties of the intrinsic semiconductor, proportional to the increase in Cr content. Finally, the sharpness of the bands of increasing intensity observed in the visible spectral region is due to the 3d-3d electronic transitions of the Cr ions [26,42]. The energy states identified in the OA spectrum of figure x (a) belong to the spin allowed and forbidden d-d transitions: 4 6a) [43].…”

Section: Cr-doped Bi 2 Te 3 Nanocrystals Embedded In Glass Systemsmentioning

confidence: 93%

“…The energy states identified in the OA spectrum of figure x (a) belong to the spin allowed and forbidden d-d transitions: 4 6a) [43]. The results are typical of inter-electronic repulsion parameters (Racah) B = 0.088 eV in a crystal field strength 10 Dq (∆) = 2.16 eV of Cr 3+ ions in coordinated octahedral sites of Te ([CrTe 6 ] 9− ) ligands [42,44].…”

Section: Cr-doped Bi 2 Te 3 Nanocrystals Embedded In Glass Systemsmentioning

confidence: 99%

“…Cr-doped Bi 2 Te 3 NCs with the atomic arrangement of monoatomic planes Te -Cr -Te -Bi -Te and Te -Bi -Te -Bi -Te in terms of quintuple layers linked by weak van der Waals interactions[41]. The substitutional doping of Cr 3+ ions with a smaller ionic radius (0.53 Å) in relation to Bi3+ (1.03 Å) distorts the environment of octahedral symmetry[42].…”

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confidence: 99%

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Doped Semiconductor Nanocrystals: Development and Applications

Silva¹,

Alvin²,

Santos³

et al. 2021

Nanocrystals [Working Title]

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This chapter aims to show significant progress that our group has been developing and the applications of several doped semiconductor nanocrystals (NCs), as nanopowders or embedded in glass systems. Depending on the type of dopant incorporated in the nanocrystals, the physical, chemical, and biological properties can be intensified. However, it can also generate undesired toxic effects that can potentially compromise its use. Here we present the potential of zinc oxide NCs doped with silver (Ag), gold (Au), and magnesium (Mg) ions to control bacterial diseases in agriculture. We have also performed biocompatibility analysis of the pure and Ag-doped sodium titanate (Na2Ti3O7) NCs in Drosophila. The doped nanocrystals embedded in glassy systems are chrome (Cr) or copper (Cu) in ZnTe and Bi2Te3 NCs for spintronic development nanodevices. Therefore, we will show several advantages that doped nanocrystals may present in the technological and biotechnological areas.

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Section: Cr-doped Bi 2 Te 3 Nanocrystals Embedded In Glass Systemsmentioning

confidence: 93%

Section: Cr-doped Bi 2 Te 3 Nanocrystals Embedded In Glass Systemsmentioning

confidence: 99%

See 1 more Smart Citation

Doped Semiconductor Nanocrystals: Development and Applications

Silva¹,

Alvin²,

Santos³

et al. 2021

Nanocrystals [Working Title]

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“…Bi 2 S 3 semiconductor nanocrystals (NCs) present radioactive recombination of electron-hole carriers adjustable according to the temperature, time, and concentration of doping ions in the system [15,[35][36][37]. The occupation of vacancies in the Bi 2 S 3 orthorhombic network by Co 2+ ions (0.72 A)  replacing Bi 3+ ions (1.03 A)  can reduce intrinsic point defects and consequently increase the efficiency of semiconductor nanocrystals, for applications in solar cells [38], photocatalytic devices of visible light [39], thermoelectric [40] and spintronic [41].…”

Section: Effects Of Symmetry and Concentration Of Cobalt-doped Bi 2 S 3 Nanocrystals Embedded In Host Glass Matrixmentioning

confidence: 99%

“…Furthermore, the p-d and spin-orbit interactions in an asymmetric tetrahedral coordination complex [CoS 4 ] 6− provide a higher intensity for 3d-3d transitions [14,15,20,42]. Therefore, the exotic properties of these new materials called diluted magnetic semiconductors (DMS) NCs are linked to the nature of the sp-d exchange interaction that occurs between the charge carriers of the Bi 2 S 3 semiconductor bands around the electrons in the central metal ion orbital (Co 2+ ) with 3d 7 electronic configuration (spin) 3d 7 (S = 3/2) [15,20,36,42]. For Bi 2-x Co x S 3 NCs, the spin allowed transitions 4 A 2 ( 4 F) → 4 T 1 ( 4 F) and 4 A 2 ( 4 F) → 4 T 1 ( 4 P) are obtained with the energy value of the barycenter for a normal distribution of the bands observed in the spectrum absorption in the range of 0.62-1.24 eV and 1.70-2.60 eV.…”

Section: Effects Of Symmetry and Concentration Of Cobalt-doped Bi 2 S 3 Nanocrystals Embedded In Host Glass Matrixmentioning

confidence: 99%

Diluted Magnetic Semiconductors Nanocrystals: Saturation and Modulation

Silva¹,

Barbosa²,

Silva³

et al. 2021

Nanocrystals [Working Title]

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Diluted Magnetic Semiconductor (DMS) nanocrystals are a new class of materials formed by doping the semiconductor with transition metals (TM), which gives interesting magneto-optical properties. These properties are attributed to the exchange interaction between the pure semiconductor’s sp-electrons and the localized TM d-electrons. This book chapter shows exciting results of new DMS developed by the group, both in powder form and embedded in glassy systems. Depending on the concentration of doping ions, saturation of the incorporation of substitutional and interstitial sites in the nanocrystal structure may occur, forming other nanocrystals. In this context, we investigated the doping saturation limit in nanopowders of DMS Zn1-xMnxO NCs and Zn1-xMnxTe, Zn0.99-xMn0.01CoxTe, and Bi2-xCoxS NCs synthesized in glassy matrices. Thus, the sites’ saturation into the crystalline lattice of nanocrystals is a topic little reported in the literature, and we will comment on this work. Therefore, we will show results from the group about the modulation and saturation in diluted magnetic semiconductors nanocrystals in this work.

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High‐Throughput Strategies in the Discovery of Thermoelectric Materials

Deng,

Qiu,

Yin

et al. 2024

Advanced Materials

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Searching for new high‐performance thermoelectric (TE) materials that are economical and environmentally friendly is an urgent task for TE society, but the advancements are greatly limited by the time‐consuming and high cost of traditional trial‐and‐error method. The significant progresses achieved in the computing hardware, efficient computing methods, advance artificial intelligence algorithms, and rapidly growing material data have brought a paradigm shift in the investigation of TE materials. Many electrical and thermal performance descriptors have been proposed and efficient high‐throughput calculation methods have been developed with the purpose to quickly screen new potential TE materials from the material databases. Some high‐throughput experiment methods have also been developed which can increase the density of information obtained in a single experiment with less time and lower cost. In addition, the machine learning methods have been also introduced in thermoelectrics. In this review, we systematically summarize the high‐throughput strategies in the discovery of TE materials. The applications of performance descriptor, high‐throughput calculation, high‐throughput experiment, and machine learning in the discovery of new TE materials are reviewed. In addition, the challenges and possible directions in the future research are also discussed.This article is protected by copyright. All rights reserved

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Investigations of structural and optical properties of Bi2−xCrxS3 nanocrystals embedded in host glass

Cited by 13 publications

References 68 publications

Doped Semiconductor Nanocrystals: Development and Applications

Doped Semiconductor Nanocrystals: Development and Applications

Diluted Magnetic Semiconductors Nanocrystals: Saturation and Modulation

High‐Throughput Strategies in the Discovery of Thermoelectric Materials

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