Nanocrystalline Oxides: CdS nanowires synthesized by solvothermal method

Recent advances in the field of nanotechnology produced an assortment of one-dimensional (1D) structures, such as nanowires and nanorods. These fascinating materials are the potential building blocks for a wide range of nanoscale electronics, optoelectronics, magnetoelectronics, or sensing devices [1]. Parallel to the success with group IV and groups III–V compounds semiconductor nanostructures, semiconducting metal oxide materials with wide band gaps are attracting attention [2-3]. The main aim of this communication is to report our results on the application of several new techniques, particularly the use of hydrothermal synthesis, to fabricate single crystal one-dimensional nanostructured materials, study their growth processes, understand the growth mechanisms and investigate their physical properties. A wide range of remarkable features are then presented, to cover a number of metal oxides, such as ZnO, Sb2O3, CdS, MgO, α-Fe2O3, or TiO2, describing their structures, optical, magnetic, mechanical and chemical sensing properties. These studies constitute the basis for developing versatile applications based on metal oxide 1D systems as well as highlighting the current progress in device development. To exemplify, the as-prepared CdS nanowires have average 28 nm in diameter and length up to several micrometres. The direct band gap of the CdS nanowires is 2.56 eV calculated by the UV-vis absorption spectra. The PL spectrum has two distinct emission bands at 502 nm and 695 nm, which are associated with the near-band-edge emission and defect emission, respectively. These synthesized single-crystal CdS nanowires have a high potential in the optoelectronic applications of nanolasers, solar cells, lighting-emitting diodes or photodetectors. Acknowledgments: Erasmus Mundus MEDASTAR (Mediterranean Area for Science, Technology and Research) Programme, 2011–4051/002–001-EMA2, Spanish MINECO (MAT2010-15094, Factoría de Cristalización – Consolider Ingenio 2010) and ERDF.

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Polyhalides as scaffolds for supramolecular, ion-conducting crown ether stacks

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314093656 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C634-C634

Author(s):

Katharina Fromm ◽

Aurélien Crochet ◽

Cyrille Dagri ◽

Yvens Chérémond

Keyword(s):

Solid State ◽

Single Crystal ◽

Crown Ethers ◽

Halogen Bonding ◽

Building Blocks ◽

Channel Formation ◽

One Dimensional ◽

Naoh Solution ◽

Ion Conducting

"Crown ethers, such as dibenzo-18-crown-6 (DB18C6) are in principle perfect building blocks to be stacked on top of each other for one-dimensional (1D) channel formation. However, in the more than 1000 publications on crown ethers in the solid state, only one case was of channel formation described, but not as main focus of research.[1] We now present a way to systematically induce the stacking of DB18C6 with the help of polyhalides, which play the roles of scaffolds via halogen bonding.[2] These compounds can be considered as ""supramolecular straws"". Using for example potassium as couter ion for triiodide for example, we obtained a solid which contains three differently filled, parallel channels in the solid state, which are arranged between the polyhalide anions. Exchanging potassium with sodium by immersion of a single crystal into NaOH solution leads to a single-crystal-to-single-crystal transformation into a compound with two channel types. This transition from a system crystallizing initially in the P2-space group to yield a compound in Pccn is only possible under these very special conditions. We will further present how the ion transport through these channels can be quantified and which process is involved in ion exchange. The role of the polyhalide anions, which cannot be replaced by other linear anions, will be emphasized as well. "

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Effect of Remote Hydrogen Plasma Treatment on ZnO Single Crystal Surfaces

MRS Proceedings ◽

10.1557/proc-744-m3.9 ◽

2002 ◽

Vol 744 ◽

Cited By ~ 3

Author(s):

Yuri M. Strzhemechny ◽

John Nemergut ◽

Junjik Bae ◽

David C. Look ◽

Leonard J. Brillson

Keyword(s):

Single Crystal ◽

Plasma Treatment ◽

Hydrogen Plasma ◽

Free Exciton ◽

Chemical Vapor Transport ◽

Near Band Edge ◽

Band Edge Emission ◽

Exciton Transition ◽

Near Surface ◽

Pl Spectra

ABSTRACTWe have studied the effects of hydrogen plasma treatment on the defect characteristics in single crystal ZnO grown at Eagle-Picher by chemical vapor transport. Depth-dependent cathodoluminescence (CL) spectra, temperature-dependent (9–300 K) and excitation intensity-dependent photoluminescence (PL) spectra reveal significant changes resulting from unannealed exposure of n-type ZnO to a remote hydrogen plasma. Low temperature PL spectra show that this hydrogen exposure effectively suppresses the free-exciton transition and redistributes intensities in the bound-exciton line set and two-electron satellites with their phonon replicas. The resultant spectra after hydrogenation exhibit a new peak feature at 3.366 eV possibly related to a neutral donor bound exciton. A simple thermal analysis of the activation energy for the 3.366 eV line yields 5–10 meV. Hydrogenation also produces a violet 100 meV-wide peak centered at 3.16 eV. Remote plasma hydrogenation produces similar changes in room-temperature CL spectra: near-band edge emission intensity increases with hydrogenation. Furthermore, this new emission increases with proximity to the free ZnO surfaces, i.e., with decreasing the energy of the incident electron beam from 3.0 down to 0.5 keV. Subsequent annealing at 450 °C completely restores both the PL and CL spectra in the sub-band gap range. The appearance of a new bound-exciton feature at 3.366 eV with H plasma exposure, the near-surface nature of the spectral changes, and the reversibility of spectral features with annealing indicate a direct link between H indiffusion and appearance of a shallow donor.

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Influence of Metal Oxide Particles on Bandgap of 1D Photocatalysts Based on SrTiO3/PAN Fibers

Nanomaterials ◽

10.3390/nano10091734 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1734

Author(s):

Fail Sultanov ◽

Chingis Daulbayev ◽

Seitkhan Azat ◽

Kairat Kuterbekov ◽

Kenzhebatyr Bekmyrza ◽

...

Keyword(s):

Metal Oxide ◽

Near Infrared ◽

Ultraviolet Region ◽

One Dimensional ◽

Composite Photocatalysts ◽

Wide Range ◽

Production Of Hydrogen ◽

Electrospinning Method ◽

Oxide Particles

This paper deals with the study of the optical properties of one-dimensional SrTiO3/PAN-based photocatalysts with the addition of metal oxide particles and the determination of their bandgaps. One-dimensional photocatalysts were obtained by the electrospinning method. Particles of metals such as iron, chromium, and copper were used as additives that are capable of improving the fibers’ photocatalytic properties based on SrTiO3/PAN. The optimal ratios of the solutions for the electrospinning of fibers based on SrTiO3/PAN with the addition of metal oxide particles were determined. The transmission and reflection of composite photocatalysts with metal oxide particles were measured in a wide range of spectra, from the ultraviolet region (185 nm) to near-infrared radiation (3600 nm), to determine the values of their bandgaps. Thus, the introduction of metal oxide particles resulted in a decrease in the bandgaps of the obtained composite photocatalysts compared to the initial SrTiO3/PAN (3.57 eV), with the following values: −3.11 eV for SrTiO3/PAN/Fe2O3, −2.84 eV for SrTiO3/PAN/CuO, and −2.89 eV for SrTiO3/PAN/Cr2O3. The obtained composite photocatalysts were tested for the production of hydrogen by the splitting of water–methanol mixtures under UV irradiation, and the following rates of hydrogen evolution were determined: 344.67 µmol h−1 g−1 for SrTiO3/PAN/Fe2O3, 398.93 µmol h−1 g−1 for SrTiO3/PAN/Cr2O3, and 420.82 µmol h−1 g−1 for SrTiO3/PAN/CuO.

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ZnO Nanosquids: Branching Nanowires from Nanotubes and Nanorods

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.n15 ◽

2008 ◽

Vol 8 (1) ◽

pp. 233-236 ◽

Cited By ~ 10

Author(s):

Samuel L. Mensah ◽

Abhishek Prasad ◽

Jiesheng Wang ◽

Yoke Khin Yap

Keyword(s):

Building Blocks ◽

Band Edge Emission ◽

Edge Emission ◽

One Dimensional ◽

Nanoelectronic Devices ◽

Si Substrates ◽

Nanophotonic Devices ◽

Crystal Growth Mechanism ◽

Sharp Band ◽

Solid Crystal

One-dimensional (1D) semiconductor nanostructures are promising building blocks for future nano-electronic and nanophotonic devices. ZnO has proven to be a multifunctional and multistructural nanomaterial with promising properties. Here we report the growth of ZnO nanosquids which can be directly grown on planar oxidized Si substrates without using catalysts and templates. The formation of these nanosquids can be explained by the theory of nucleation, and the vapor-solid crystal growth mechanism. The branching nanowires of these ZnO nanosquids could have potential application in multiplexing future nanoelectronic devices. The sharp band-edge emission at ∼380 nm indicates that these ZnO nanosquids are also applicable for interesting optoelectronic devices.

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Enhancement of the core near-band-edge emission induced by an amorphous shell in coaxial one-dimensional nanostructure: the case of SiC/SiO2core/shell self-organized nanowires

Nanotechnology ◽

10.1088/0957-4484/21/34/345702 ◽

2010 ◽

Vol 21 (34) ◽

pp. 345702 ◽

Cited By ~ 34

Author(s):

Filippo Fabbri ◽

Francesca Rossi ◽

Giovanni Attolini ◽

Giancarlo Salviati ◽

Salvatore Iannotta ◽

...

Keyword(s):

Band Edge ◽

Near Band Edge Emission ◽

Near Band Edge ◽

Band Edge Emission ◽

Edge Emission ◽

One Dimensional ◽

The Core ◽

Self Organized

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Correlation between the internal quantum efficiency and photoluminescence lifetime of the near-band-edge emission in a ZnO single crystal grown by the hydrothermal method

Applied Physics Express ◽

10.35848/1882-0786/abcd73 ◽

2020 ◽

Vol 13 (12) ◽

pp. 121005

Author(s):

Kazunobu Kojima ◽

Shigefusa F. Chichibu

Keyword(s):

Single Crystal ◽

Hydrothermal Method ◽

Quantum Efficiency ◽

Internal Quantum Efficiency ◽

Band Edge ◽

Near Band Edge ◽

Band Edge Emission ◽

Edge Emission ◽

Photoluminescence Lifetime ◽

Zno Single Crystal

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Linear One-Dimensional Coordination Polymers Constructed by Dirhodium Paddlewheel and Tetracyanido-Metallate Building Blocks

Crystals ◽

10.3390/cryst9120614 ◽

2019 ◽

Vol 9 (12) ◽

pp. 614 ◽

Cited By ~ 2

Author(s):

David Prior ◽

Miguel Cortijo ◽

Rodrigo González-Prieto ◽

Santiago Herrero ◽

Reyes Jiménez-Aparicio ◽

...

Keyword(s):

Single Crystal ◽

Coordination Polymers ◽

Chloroform Solution ◽

Building Blocks ◽

X Ray Diffraction ◽

Dichloromethane Solution ◽

Space Group ◽

One Dimensional ◽

X Ray ◽

Group A

In this article, we describe the preparation of anionic heteronuclear one-dimensional coordination polymers made by dirhodium paddlewheels and tetracyanido-metallatate building blocks. A series of complexes of (PPh4)2n[{Rh2(µ-O2CCH3)4}{M(CN)4}]n (M = Ni (1), Pd (2), Pt (3)) formulae were obtained by reaction of [Rh2(μ-O2CCH3)4] with (PPh4)2[M(CN)4] in a 1:1 or 2:1 ratio. Crystals of 1−3 suitable for single crystal X-ray diffraction were grown by slow diffusion of a dichloromethane solution of the dirhodium complex into a chloroform solution of the corresponding tetracyanido–metallatate salt. Compounds 1 and 2 are isostructural and crystallize in the triclinic P-1 space group, while compound 3 crystallizes in the monoclinic P21/n space group. A detailed description of the structures is presented, including the analysis of the packing of anionic chains and PPh4+ cations.

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Toward Quantum Line−Self-Assembly Process of Nanomolecular Building Blocks Leading to a Novel One-Dimensional Nanomolecular Polymer: Single-Crystal X-ray Structure of {[H3O]+12{(H2O)MoO2.5[Mo36O108(NO)4(H2O)16]- O2.5Mo(H2O)}12-}n

Journal of the American Chemical Society ◽

10.1021/ja961637e ◽

1997 ◽

Vol 119 (27) ◽

pp. 6440-6441 ◽

Cited By ~ 41

Author(s):

Shi-Wei Zhang ◽

Yong-Ge Wei ◽

Qing Yu ◽

Mei-Cheng Shao ◽

You-Qi Tang

Keyword(s):

Single Crystal ◽

Self Assembly ◽

Building Blocks ◽

Assembly Process ◽

One Dimensional ◽

X Ray

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Synthesis of formamidinium lead iodide perovskite bulk single crystal and its optical properties

International Journal of Modern Physics B ◽

10.1142/s0217979217440660 ◽

2017 ◽

Vol 31 (16-19) ◽

pp. 1744066 ◽

Cited By ~ 1

Author(s):

Hongge Zheng ◽

Junjie Duan ◽

Jun Dai

Keyword(s):

Single Crystal ◽

Orthorhombic Phase ◽

Near Band Edge ◽

Cubic Phase ◽

Band Edge Emission ◽

Bulk Single Crystal ◽

Lead Iodide ◽

Temperature Dependent ◽

Recombination Mechanism ◽

Pl Spectra

Formamidinium lead iodide (FAPbI3) is a promising hybrid perovskite material for optoelectronic devices. We synthesized bulk single crystal FAPbI3 by a rapid solution crystallization method. X-ray diffraction (XRD) was performed to characterize the crystal structure. Temperature-dependent photoluminescence (PL) spectra of the bulk single crystal FAPbI3 were measured from 10 to 300 K to explain PL recombination mechanism. It shows that near band edge emission blueshifts with the temperature increasing from 10 to 120 K and from 140 K to room temperature, a sudden emission band redshift demonstrates near 140 K because of the phase transition from orthorhombic phase to cubic phase. From the temperature-dependent PL spectra, the temperature coefficients of the bandgap and thermal activation energies of FAPbI3 perovskite are fitted.

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