The MBE Growth and Optical Quality of BaTiO3 and SrTiO3Thin Films on MgO

1994 ◽  
Vol 341 ◽  
Author(s):  
R. A. McKee ◽  
F. J. Walker ◽  
E. D. Specht ◽  
K. B. Alexander
Keyword(s):  
Optical Loss ◽  
Wavelength Dependence ◽  
Optical Quality ◽  
High Quality ◽  
High Optical Quality ◽  
Mbe Growth ◽  
Cell Height ◽  
Out Of Plane ◽  
Loss Coefficients

AbstractHigh quality epitaxial BaTiO3 and SrTiO3 have been grown on MgO, stabilized at a one unit cell height, and grown to film thicknesses of 0.5 - 0.7 μm. These relatively thick films remain adherent when thermally cycled between growth temperatures and room temperature, are crack free with high optical quality, and have both in-plane and out-of-plane X-ray rocking curves of 0.3–0.5°. These films have been grown using molecular beam epitaxy (MBE) methods starting with the TiO2 layer of the perovskite structure. The TiO2-Iayer/MgO interface uniquely satisfies electrostatic requirements for perovskite heteroepitaxy and provides the template structure that leads to the high quality films that are obtained. Wavelength dependence of optical loss has been characterized between 475 nm and 705 nm with loss coefficients < 1dB/cm being obtained at the He-Ne wavelength.

scholarly journals Printability of papers recycled from toner and inkjet-printed papers after deinking and recycling processes

2017 ◽  
Vol 16 (2) ◽  
pp. 76-82
Author(s):  
Arif Karademir ◽  
Cem Aydemir ◽  
Dogan Tutak ◽  
Raja Aravamuthan
Keyword(s):  
High Efficiency ◽  
Color Change ◽  
Paper Industry ◽  
Optical Quality ◽  
Recycled Paper ◽  
High Optical Quality ◽  
Contemporary World ◽  
Before And After ◽  
Better Than

Background: In our contemporary world, while part of the fibers used in the paper industry is obtained from primary fibers such as wood and agricultural plants, the rest is obtained from secondary fibers from waste papers. To manufacture paper with high optical quality from fibers of recycled waste papers, these papers require deinking and bleaching of fibers at desired levels. High efficiency in removal of ink from paper mass during recycling, and hence deinkability, are especially crucial for the optical and printability quality of the ultimate manufactured paper. Methods: In the present study, deinkability and printability performance of digitally printed paper with toner or inkjet ink were compared for the postrecycling product. To that end, opaque 80 g/m2 office paper was digitally printed under standard printing conditions with laser toner or inkjet ink; then these sheets of paper were deinked by a deinking process based on the INGEDE method 11 p. After the deinking operation, the optical properties of the obtained recycled handsheets were compared with unprinted (reference) paper. Then the recycled paper was printed on once again under the same conditions as before with inkjet and laser printers, to monitor and measure printing color change before and after recycling, and differences in color universe. Results: Recycling and printing performances of water-based inkjet and toner-based laser printed paper were obtained. The outcomes for laser-printed recycled paper were better than those for inkjet-printed recycled paper. Conclusions: Compared for luminosity Y, brightness, CIE a* and CIE b* values, paper recycled from laser-printed paper exhibited higher value than paper recycled from inkjet-printed paper.

scholarly journals III-V nanowires with quantum dots: MBE growth and properties

2021 ◽  
Vol 2015 (1) ◽  
pp. 012124
Author(s):  
R R Reznik ◽  
K P Kotlyar ◽  
V O Gridchin ◽  
I V Ilkiv ◽  
A I Khrebtov ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Optoelectronic Devices ◽  
Optical Quality ◽  
Silicon Substrates ◽  
Single Photons ◽  
Mbe Growth ◽  
Pl Spectrum ◽  
Good Optical Quality

Abstract We demonstrate growth of AlGaAs NWs with GaAs QDs and InP NWs with InAsP QDs on silicon substrates. Results of GaAs QDs optical properties study have shown that these objects are sources of single photons. In case of InP NWs with InAsP QDs, the results showed that ~ 100% of homogeneously oriented NWs were formed with good optical quality of this system on a Si(111). PL spectrum peak near 1.3 μm indicates that such system is promising for optoelectronic devices.

scholarly journals GaAs epilayers grown on patterned (001) silicon substrates via suspended Ge layers

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Andrea Ballabio ◽  
Sergio Bietti ◽  
Andrea Scaccabarozzi ◽  
Luca Esposito ◽  
Stefano Vichi ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Thermal Strain ◽  
Gaas Layer ◽  
Optical Quality ◽  
Silicon Substrates ◽  
Phase Boundaries ◽  
High Optical Quality ◽  
Quantum Well Structures ◽  
Si Substrates

AbstractWe demonstrate the growth of low density anti-phase boundaries, crack-free GaAs epilayers, by Molecular Beam Epitaxy on silicon (001) substrates. The method relies on the deposition of thick GaAs on a suspended Ge buffer realized on top of deeply patterned Si substrates by means of a three-temperature procedure for the growth. This approach allows to suppress, at the same time, both threading dislocations and thermal strain in the epilayer and to remove anti-phase boundaries even in absence of substrate tilt. Photoluminescence measurements show the good uniformity and the high optical quality of AlGaAs/GaAs quantum well structures realized on top of such GaAs layer.

MBE growth of InAs/GaAs quantum dots on sintered porous silicon substrates with high optical quality in the 1.3 μm band

2020 ◽  
Vol 31 (6) ◽  
pp. 4605-4610 ◽  
Author(s):  
Mansour Aouassa ◽  
Giorgia Franzò ◽  
Elie Assaf ◽  
Larbi Sfaxi ◽  
Ridha M’Ghaieth ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Porous Silicon ◽  
Optical Quality ◽  
Silicon Substrates ◽  
High Optical Quality ◽  
Mbe Growth

scholarly journals Fluorescent Aptamer Immobilization on Inverse Colloidal Crystals

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4326 ◽  
Author(s):  
Andrea Chiappini ◽  
Laura Pasquardini ◽  
Somayeh Nodehi ◽  
Cristina Armellini ◽  
Nicola Bazzanella ◽  
...  
Keyword(s):  
Band Gap ◽  
Photonic Band Gap ◽  
Transmission Band ◽  
Optical Quality ◽  
Dna Aptamer ◽  
Inverse Opal ◽  
High Optical Quality ◽  
Inverse Opals ◽  
Assembly Method

In this paper, we described a versatile two steps approach for the realization of silica inverse opals functionalized with DNA-aptamers labelled with Cy3 fluorophore. The co-assembly method was successfully employed for the realization of high quality inverse silica opal, whilst the inverse network was functionalized via epoxy chemistry. Morphological and optical assessment revealed the presence of large ordered domains with a transmission band gap depth of 32%, after the functionalization procedure. Finite Difference Time-Domain (FDTD) simulations confirmed the high optical quality of the inverse opal realized. Photoluminescence measurements evidenced the effective immobilization of DNA-aptamer molecules labelled with Cy3 throughout the entire sample thickness. This assumption was verified by the inhibition of the fluorescence of Cy3 fluorophore tailoring the position of the photonic band gap of the inverse opal. The modification of the fluorescence could be justified by a variation in the density of states (DOS) calculated by the Plane Wave Expansion (PWE) method. Finally, the development of the aforementioned approach could be seen as proof of the concept experiment, suggesting that this type of system may act as a suitable platform for the realization of fluorescence-based bio-sensors.

Band Gap Change of Bulk ZnSxSe1–x Semiconductors by Controlling the Sulfur Content

2018 ◽  
Vol 63 (1) ◽  
pp. 33 ◽  
Author(s):  
O. G. Trubaieva ◽  
A. I. Lalayants ◽  
M. A. Chaika
Keyword(s):  
Band Gap ◽  
Sulfur Content ◽  
Optical Band Gap ◽  
Optical Quality ◽  
Bulk Crystals ◽  
High Optical Quality ◽  
New States ◽  
Stockbarger Method

ZnSxSe1−x bulk crystals were grown by the Bridgman–Stockbarger method. The transmittance of different samples in the range from 67% to 56% at la = 1100 nm (for 4-mm samples) indicates a high optical quality of the crystals. No new states were revealed at the sulfur incorporation, and the band gap depends on the composition. The optical band gap of ZnSxSe1−x bulk crystals varies from 2.59 to 2.78 eV for direct transitions and from 2.49 to 2.70 eV for indirect transitions.

scholarly journals High optical quality of MoS 2 monolayers grown by chemical vapor deposition

2D Materials ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 015011 ◽  
Author(s):  
Shivangi Shree ◽  
Antony George ◽  
Tibor Lehnert ◽  
Christof Neumann ◽  
Meryem Benelajla ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Optical Quality ◽  
High Optical Quality

scholarly journals Improved optical activation of ion-implanted Zn acceptors in GaN by annealing under N2 overpressure

1997 ◽  
Vol 2 ◽  
Author(s):  
A. Pelzmann ◽  
S. Strite ◽  
A. Dommann ◽  
C. Kirchner ◽  
Markus Kamp ◽  
...  
Keyword(s):  
Optical Quality ◽  
X Ray Diffraction ◽  
High Optical Quality ◽  
X Ray ◽  
Mocvd Reactor ◽  
Defect Annealing ◽  
Optical Activation ◽  
Gan Crystal ◽  
Ion Implanted

We investigated the properties of ion-implanted GaN:Zn annealed under various conditions using photoluminescence (PL) and high resolution x-ray diffraction (HRXRD). Epitaxial GaN/sapphire of high optical quality was ion-implanted with a 1013 cm−2 dose of Zn+ ions at 200 keV. The sample was capped with 200 Å of SiNx and then diced into numerous pieces which were annealed under varied conditions in an attempt to optically activate the Zn. Annealing was performed in a tube furnace under flowing N2, an atmospheric pressure MOCVD reactor under flowing NH3 or N2, and under an N2 overpressure of 190 atm. The observed improvement in the optical quality of GaN:Zn annealed under N2 overpressure yields further insights into the trade-off between defect annealing and N loss from the GaN crystal.

scholarly journals III-V nanostructures with different dimensionality on silicon

2021 ◽  
Vol 2103 (1) ◽  
pp. 012121
Author(s):  
R R Reznik ◽  
K P Kotlyar ◽  
V O Gridchin ◽  
I V Ilkiv ◽  
A I Khrebtov ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Quality ◽  
Silicon Substrates ◽  
Single Photons ◽  
Optical Elements ◽  
High Optical Quality ◽  
Bandgap Semiconductors ◽  
Optic Systems ◽  
The Given

Abstract The possibility of AlGaAs nanowires with GaAs quantum dots and InP nanowires with InAsP quantum dots growth by molecular-beam epitaxy on silicon substrates has been demonstrated. Results of GaAs quantum dots optical properties studies have shown that these objects are sources of single photons. In case of InP nanowires with InAsP quantum dots, the results we obtained indicate that nearly 100% of coherent nanowires can be formed with high optical quality of this system on a silicon surface. The presence of a band with maximum emission intensity near 1.3 μm makes it possible to consider the given system promising for further integration of optical elements on silicon platform with fiber-optic systems. Our work, therefore, opens new prospects for integration of direct bandgap semiconductors and singlephoton sources on silicon platform for various applications in the fields of silicon photonics and quantum information technology.

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