Structural Design and Band Gap Properties of 3D Star-Shaped Single-Phase Metamaterials

2022 ◽  
Author(s):  
Fen Yu ◽  
Yueli Huo ◽  
Qian Ding ◽  
Cong Wang ◽  
Jinxin Yao ◽  
...  
Keyword(s):  
Band Gap ◽  
Structural Design ◽  
Single Phase

scholarly journals Transparent All-Oxide Hybrid NiO:N/TiO2 Heterostructure for Optoelectronic Applications

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 988
Author(s):  
Chrysa Aivalioti ◽  
Alexandros Papadakis ◽  
Emmanouil Manidakis ◽  
Maria Kayambaki ◽  
Maria Androulidaki ◽  
...  
Keyword(s):  
Band Gap ◽  
Single Phase ◽  
Structural Disorder ◽  
Energy Band Gap ◽  
Nitrogen Doped ◽  
Nio Thin Film ◽  
Direct Band ◽  
Output Characteristics ◽  
Indirect Band Gap ◽  
P Type

Nickel oxide (NiO) is a p-type oxide and nitrogen is one of the dopants used for modifying its properties. Until now, nitrogen-doped NiO has shown inferior optical and electrical properties than those of pure NiO. In this work, we present nitrogen-doped NiO (NiO:N) thin films with enhanced properties compared to those of the undoped NiO thin film. The NiO:N films were grown at room temperature by sputtering using a plasma containing 50% Ar and 50% (O2 + N2) gases. The undoped NiO film was oxygen-rich, single-phase cubic NiO, having a transmittance of less than 20%. Upon doping with nitrogen, the films became more transparent (around 65%), had a wide direct band gap (up to 3.67 eV) and showed clear evidence of indirect band gap, 2.50–2.72 eV, depending on %(O2-N2) in plasma. The changes in the properties of the films such as structural disorder, energy band gap, Urbach states and resistivity were correlated with the incorporation of nitrogen in their structure. The optimum NiO:N film was used to form a diode with spin-coated, mesoporous on top of a compact, TiO2 film. The hybrid NiO:N/TiO2 heterojunction was transparent showing good output characteristics, as deduced using both I-V and Cheung’s methods, which were further improved upon thermal treatment. Transparent NiO:N films can be realized for all-oxide flexible optoelectronic devices.

Structural and Electronic Properties of (CdTe)1−x(In2Te3)x Films Grown by Close-spaced vapor Transport Combined with Free Evaporation

2000 ◽  
Vol 15 (8) ◽  
pp. 1811-1815 ◽  
Author(s):  
M. Zapata-Torres ◽  
Y. P. Mascarenhas ◽  
M. A. Santana-Aranda ◽  
J. Luyo-Alvarado ◽  
M. Melé-Lirandez ◽  
...  
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Single Phase ◽  
Vapor Transport ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Value ◽  
Structural And Electronic Properties ◽  
Direct Band ◽  
Transmission Measurements

The structural and electronic properties of (CdTe)1−x(In2Te3)x thin films as a function of substrate temperature were studied using x-ray diffraction, energy dispersive x-ray analysis, and Raman, transmission, and modulated transmission spectroscopies. The films were grown by the close-spaced vapor transport technique combined with free evaporation; CdTe and In2Te3 were used as sources. From x-ray diffraction the presence of mixed phases and differences in composition were detected, and good correlation with Raman spectroscopy was found. Transmission spectroscopy suggested the possibility of a modulation of the band gap of the alloy from a value as low as 0.5 eV up to 1.5 eV. Single-phase films presented a direct band gap of around 1.15 eV, as obtained from modulated transmission measurements.

scholarly journals Single phase 3D phononic band gap material

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Franziska Warmuth ◽  
Maximilian Wormser ◽  
Carolin Körner
Keyword(s):  
Band Gap ◽  
Single Phase ◽  
Phononic Band Gap

Novel single-phase white-emitting phosphor Sr6Gd2Na2(PO4)6F2:Eu2+,Mn2+: band gap, luminescence, and energy transfer

2016 ◽  
Vol 27 (11) ◽  
pp. 11713-11719 ◽  
Author(s):  
Anxiang Guan ◽  
Peican Chen ◽  
Guofang Wang ◽  
Liya Zhou ◽  
Yingbin Meng ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Band Gap ◽  
Single Phase

Single Phase CuO Thin Films Prepared by Thermal Oxidation in Air with Water Vapor

2015 ◽  
Vol 1109 ◽  
pp. 544-548 ◽  
Author(s):  
Jian Bo Liang ◽  
Xu Yang Li ◽  
Naoki Kishi ◽  
Tetsuo Soga
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Optical Properties ◽  
Water Vapor ◽  
Band Gap ◽  
Thermal Oxidation ◽  
Single Phase ◽  
Optical Band Gap ◽  
Structural And Optical Properties ◽  
Oxidation In Air

Single phase CuO films have been successfully synthesized by thermal oxidation of cupper foil in air with water vapor. The structural and optical properties of CuO films were investigated. It is observed that the grain size increases with increasing the oxidation temperature. The optical band gap of CuO film is determined by the transmittance and reflectance spectra.

scholarly journals Anion Distribution, Structural Distortion, and Symmetry-Driven Optical Band Gap Bowing of Mixed Halide Cs2SnX6 Vacancy Ordered Double Perovskites

2019 ◽  
Author(s):  
Maham Karim ◽  
Alex Ganose ◽  
Laura Pieters ◽  
Winnie Leung ◽  
Jess Wade ◽  
...  
Keyword(s):  
Band Gap ◽  
Single Phase ◽  
Optical Band Gap ◽  
Local Symmetry ◽  
Phase Method ◽  
Composition Series ◽  
Temperature Solution ◽  
Anion Distribution ◽  
A Site ◽  
Solution Phase Method

Mixed anion compounds in the Fm-3m vacancy ordered perovskite structure were synthesised and characterised experimentally and computationally with a focus on compounds where A = Cs+. Pure anion Cs<sub>2</sub>SnX<sub>6</sub> compounds were formed with X = Cl, Br and I using a room temperature solution phase method. Mixed anion compounds were formed as solid solutions of Cs<sub>2</sub>SnCl<sub>6</sub> and Cs<sub>2</sub>SnBr<sub>6</sub> and a second series from Cs<sub>2</sub>SnBr<sub>6</sub> and Cs<sub>2</sub>SnI<sub>6</sub>. Single phase structures formed across the entirety of both composition series, with no evidence of long range anion ordering observed by diffraction. A distortion of the cubic A2BX6 structure was identified in which the spacing of the BX6 octahedra changes to accommodate the A site cation without reduction of overall symmetry. Optical band gap values varied with anion composition between 4.89 eV in Cs<sub>2</sub>SnCl<sub>6 </sub>to 1.35 eV in Cs<sub>2</sub>SnI<sub>6</sub>, but proved highly non-linear with changes in composition. In mixed halide compounds it was found that lower energy optical transitions appeared that were not present in the pure halide compounds, and this could be attributed to lowering of the local symmetry within the tin halide octahedra. The electronic structure was characterised by photoemission spectroscopy, and Raman spectroscopy revealed vibrational modes in the mixed halide compounds that could be assigned to particular mixed halide octahedra. This analysis was used to determine the distribution of octahedra types in mixed anion compounds, which was found to be consistent with a near-random distribution of halide anions throughout the structure, although some deviations from random halide distribution were noted in mixed iodide-bromide compounds, where the larger iodide anions preferentially adopted trans configurations.

Dibenzopyran-Based Wide Band Gap Conjugated Copolymers: Structural Design and Application for Polymer Solar Cells

2016 ◽  
Vol 8 (45) ◽  
pp. 31348-31358 ◽  
Author(s):  
Yuanyuan Zhou ◽  
Miao Li ◽  
Yijing Guo ◽  
Heng Lu ◽  
Jinsheng Song ◽  
...  
Keyword(s):  
Solar Cells ◽  
Band Gap ◽  
Structural Design ◽  
Polymer Solar Cells ◽  
Wide Band ◽  
Wide Band Gap ◽  
Design And Application ◽  
Conjugated Copolymers

The Effect of Annealing Temperature on the Band Gap of ZnO Nano Materials

2012 ◽  
Vol 545 ◽  
pp. 165-168 ◽  
Author(s):  
Muhd Firdaus Kasim ◽  
Rusdi Roshidah ◽  
Suraya Ahmad Kamil ◽  
Norlida Kamarulzaman
Keyword(s):  
Band Gap ◽  
Single Phase ◽  
Sol Gel ◽  
Spherical Shape ◽  
Hexagonal Structure ◽  
Nano Materials ◽  
Zinc Oxide Nanostructures ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Oxide Nanostructures

Zinc oxide nanostructures were prepared by sol-gel method without using any chelating agents. The structural and optical properties of the nanostructures were studied. The precursors were annealed at 400 °C and 800 °C for 24 hours and characterized using X-Ray diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). The band gap energies were analyzed by using a UV-Vis spectrophotometer. Based on the XRD results, all materials were single phase with the hexagonal structure without any impurities presents. Based on the FESEM results, it was found that the morphology for the materials annealed at 400 °C has nanorod shape while for the materials annealed at 800 °C, they have spherical shape. It was found that the band gap energies of the ZnO nanomaterials were dependent on the morphology of the nanostructures.

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