ChemInform Abstract: Direct and Indirect Band Gap Types in One-Dimensional Conjugated or Stacked Organic Materials

We report the first one-dimensional tubular metal-organic framework (MOF) [Ni(Cu-H6TPPA)]∙2DMA (H8TPPA = 5,10,15,20-tetrakis[p-phenylphosphonic acid] porphyrin) in the literature. The structure of this MOF, known as GTUB4, was solved using single crystal X-ray diffraction and its surface area was calculated to be 1102 m2/g, making it the phosphonate MOF with the highest reported surface area. GTUB4 also possesses a narrow indirect band gap of 1.9 eV and a direct band gap of 2.16 eV, making it a semiconducting MOF. Thermogravimetric analysis of GTUB4 suggests that it is thermally stable up to 400°C. Owing to its high surface area, low band gap, and thermal stability, GTUB4 could find applications as electrodes in supercapacitors.

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A Semiconductive and Microporous One-Dimensional Tubular Metal-Organic Framework

10.26434/chemrxiv.11920026.v1 ◽

2020 ◽

Author(s):

Mehmet Menaf Ayhan ◽

Ceyda Bayraktar ◽

Kai Yu ◽

Gabriel Hanna ◽

Ozgur Yazaydin ◽

...

Keyword(s):

Band Gap ◽

Surface Area ◽

Metal Organic Framework ◽

High Surface ◽

High Surface Area ◽

One Dimensional ◽

Metal Organic ◽

Direct Band ◽

Indirect Band Gap ◽

Organic Framework

We report the first one-dimensional tubular metal-organic framework (MOF) [Ni(Cu-H6TPPA)]∙2DMA (H8TPPA = 5,10,15,20-tetrakis[p-phenylphosphonic acid] porphyrin) in the literature. The structure of this MOF, known as GTUB4, was solved using single crystal X-ray diffraction and its surface area was calculated to be 1102 m2/g, making it the phosphonate MOF with the highest reported surface area. GTUB4 also possesses a narrow indirect band gap of 1.9 eV and a direct band gap of 2.16 eV, making it a semiconducting MOF. Thermogravimetric analysis of GTUB4 suggests that it is thermally stable up to 400°C. Owing to its high surface area, low band gap, and thermal stability, GTUB4 could find applications as electrodes in supercapacitors.

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Telluride Te2I: Electronic properties of one-dimensional atomic chains structure

E3S Web of Conferences ◽

10.1051/e3sconf/202123601028 ◽

2021 ◽

Vol 236 ◽

pp. 01028

Author(s):

Biaohua Wei ◽

Xu Han

Keyword(s):

Band Gap ◽

Electronic Conductivity ◽

Chain Structure ◽

Ultraviolet Region ◽

Atomic Chain ◽

Strong Light ◽

One Dimensional ◽

Atomic Chains ◽

Indirect Band Gap ◽

Low Dimensional

Semiconductor tellurium is an excellent performance material, tellurium and its compounds have been extensive researched in the low-dimensional field. Inspired by the synthesis of a one-dimensional tellurium atomic chains, we predict a new one-dimensional Te2I single-atomic chain structure based on firstprinciples. Using first-principles calculations, Te2I single-atomic chain has an exfoliated energy of 137.95 meV, suggesting that the exfoliation of atomic chains materials from the bulk phase could be feasible. The single-atomic chain structure is an indirect band gap semiconductor with a band gap of 1.51 eV. In addition, its dynamic and thermodynamic properties indicate that the structure is stable at room temperature. Remarkably, it exhibits good electronic conductivity and a large difference in electron and hole mobilities, indicating that it is favorable for the migration and separation of photogenerated carriers. The absorption spectrum of one-dimensional Te2I single-atomic chain exhibits a strong light-harvesting ability in the ultraviolet region, suggesting its potential application in optoelectronic devices

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Omnidirectional terahertz photonic band gap broaden effect in one-dimensional photonic crystal containing few-layer graphene

Optics Communications ◽

10.1016/j.optcom.2021.126898 ◽

2021 ◽

Vol 490 ◽

pp. 126898

Author(s):

Feng Wu ◽

Mingyuan Chen ◽

Zhanxu Chen ◽

Chengping Yin

Keyword(s):

Photonic Crystal ◽

Band Gap ◽

Photonic Band Gap ◽

One Dimensional ◽

Dimensional Photonic Crystal ◽

Layer Graphene ◽

Few Layer Graphene ◽

Photonic Band

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

Electronics ◽

10.3390/electronics10090988 ◽

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.

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Enhanced luminescence/photodetecting bifunctional devices based on ZnO:Ga microwire/p-Si heterojunction by incorporating Ag nanowires

Nanoscale Advances ◽

10.1039/d1na00428j ◽

2021 ◽

Author(s):

Mingming Jiang ◽

Yang Liu ◽

Ruiming Dai ◽

Kai Tang ◽

Peng Wan ◽

...

Keyword(s):

Band Gap ◽

Carrier Mobility ◽

Lattice Mismatch ◽

Semiconductor Materials ◽

Large Lattice ◽

Ag Nanowires ◽

Large Lattice Mismatch ◽

Enhanced Luminescence ◽

Indirect Band Gap

Suffering from the indirect band gap, low carrier mobility, and large lattice mismatch with other semiconductor materials, one of the current challenges in Si-based materials and structures is to prepare...

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Optical Studies of Poly (N-Carbazole) (PVK) Blending with Polyvinylpyrrolidone (PVP) Using Tauc/Davis-Mott Model

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.652-654.527 ◽

2013 ◽

Vol 652-654 ◽

pp. 527-531 ◽

Cited By ~ 1

Author(s):

A.N. Alias ◽

T.I. Tunku Kudin ◽

Z.M. Zabidi ◽

M.K. Harun ◽

Ab Malik Marwan Ali ◽

...

Keyword(s):

Band Gap ◽

Urbach Energy ◽

Quartz Substrate ◽

Optical Studies ◽

Direct Band Gap ◽

Mott Model ◽

Blended Polymer ◽

Electronic Parameters ◽

Direct Band ◽

Indirect Band Gap

The optical absorption spectra of blended poly (N-carbazole) (PVK) with polyvinylpyrrolidone (PVP) in various compositions are investigated. A doctor blade technique was used to coat the blended polymer on a quartz substrate. The electronic parameters such as absorption edge (Ee), allowed direct band gap (Ed), allowed indirect band gap (Ei), Urbach edge (Eu) and steepness parameter (γ) were calculated using Tauc/Davis-Mott Model. The results reveal that the Ee, Ed and Ei increase with increasing of PVP ratio. There also have variation changing in Urbach energy and steepness parameter.

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Effect of Double Defects on Transmission Spectra of One-Dimensional Photonic Crystals

Materials Science Forum ◽

10.4028/www.scientific.net/msf.663-665.725 ◽

2010 ◽

Vol 663-665 ◽

pp. 725-728 ◽

Cited By ~ 1

Author(s):

Yuan Ming Huang ◽

Qing Lan Ma ◽

Bao Gai Zhai ◽

Yun Gao Cai

Keyword(s):

Photonic Crystals ◽

Band Gap ◽

Theoretical Calculations ◽

Stop Band ◽

Band Gaps ◽

Characteristic Matrix ◽

Frequency Range ◽

Defect Band ◽

One Dimensional ◽

The One

Considered the model of the one-dimensional photonic crystals (1-D PCs) with double defects, the refractive indexes (n2’, n3’ and n2’’, n3’’) of the double defects were 2.0, 4.0 and 4.0, 2.0 respectively. With parameter n2=1.5, n3=2.5, by theoretical calculations with characteristic matrix method, the results shown that for a certain number (14 was taken) of layers of the 1-D PCs, when the double defects abutted, there was a defect band gap in the stop band gap, while when the double defects separated, there occurred two defect band gaps in the stop band gap; besides, with the separation of the two defects, the transmittance of the double defect band gaps decreased gradually. In addition, in this progress, the frequency range of the stop band gap has a little increase from 0.092 to 0.095.

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