scholarly journals Pressure dependence of the band-gap energy in BiTeI

2016 ◽  
Vol 94 (16) ◽  
Author(s):  
Sümeyra Güler-Kılıç ◽  
Çetin Kılıç
Keyword(s):  
Band Gap ◽  
Pressure Dependence ◽  
Band Gap Energy ◽  
Gap Energy

Pressure dependence of the band gap energy at Г and X for the dilute nitride GaNP alloy

2014 ◽  
Vol 608 ◽  
pp. 66-68 ◽  
Author(s):  
Chuan-Zhen Zhao ◽  
Tong Wei ◽  
Xiao-Dong Sun ◽  
Sha-Sha Wang ◽  
Ke-Qing Lu
Keyword(s):  
Band Gap ◽  
Pressure Dependence ◽  
Band Gap Energy ◽  
Dilute Nitride ◽  
Gap Energy

A pressure dependence model for the band gap energy of the dilute nitride GaNP

2014 ◽  
Vol 116 (6) ◽  
pp. 063512 ◽  
Author(s):  
Chuan-Zhen Zhao ◽  
Tong Wei ◽  
Na-Na Li ◽  
Sha-Sha Wang ◽  
Ke-Qing Lu
Keyword(s):  
Band Gap ◽  
Pressure Dependence ◽  
Band Gap Energy ◽  
Dilute Nitride ◽  
Gap Energy

A model describing the pressure dependence of the band gap energy for the group III–V semiconductors

2016 ◽  
Vol 494 ◽  
pp. 71-74 ◽  
Author(s):  
Chuan-Zhen Zhao ◽  
Tong Wei ◽  
Xiao-Dong Sun ◽  
Sha-Sha Wang ◽  
Ke-Qing Lu
Keyword(s):  
Band Gap ◽  
Pressure Dependence ◽  
Band Gap Energy ◽  
Group Iii V Semiconductors ◽  
Group Iii ◽  
Gap Energy

scholarly journals Pressure dependence of the fundamental band-gap energy of CdSe

2004 ◽  
Vol 84 (1) ◽  
pp. 67-69 ◽  
Author(s):  
W. Shan ◽  
W. Walukiewicz ◽  
J. W. Ager ◽  
K. M. Yu ◽  
J. Wu ◽  
...  
Keyword(s):  
Band Gap ◽  
Pressure Dependence ◽  
Band Gap Energy ◽  
Fundamental Band ◽  
Gap Energy

scholarly journals Pressure dependence of the band gap energy for the dilute nitride GaNxAs1−x

2016 ◽  
Vol 34 (4) ◽  
pp. 881-885 ◽  
Author(s):  
Chuan-Zhen Zhao ◽  
Tong Wei ◽  
Xiao-Dong Sun ◽  
Sha-Sha Wang ◽  
Ke-Qing Lu
Keyword(s):  
Band Gap ◽  
Pressure Dependence ◽  
Energy Difference ◽  
Band Gap Energy ◽  
Dilute Nitride ◽  
Coupling Interaction ◽  
Gap Energy ◽  
Host Interaction ◽  
Two Factors ◽  
Indirect Band Gap

AbstractA model is developed to describe the pressure dependence of the band gap energy for the dilute nitride GaNxAs1–x. It is found that the sublinear pressure dependence of E− is due to the coupling interaction between E+ and E−. We have also found that GaNxAs1−x needs much larger pressure than GaAs to realize the transition from direct to indirect band gap. It is due to two factors. One is the coupling interaction between the E+ and E−. The other is that the energy difference between the X conduction band minimum (CBM) and the G CBM in GaNxAs1−x is larger than that in GaAs. In addition, we explain the phenomenon that the energy difference between the X CBM and the G CBM in GaNxAs1−x is larger than that in GaAs. It is due to the impurity-host interaction.

Modification of optical properties of PC-PBT/Cr2O3 and PC-PBT/CdS nanocomposites by gamma irradiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20402
Author(s):  
Kaoutar Benthami ◽  
Mai ME. Barakat ◽  
Samir A. Nouh
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Color Difference ◽  
Band Gap Energy ◽  
Polybutylene Terephthalate ◽  
Γ Irradiation ◽  
Gap Energy ◽  
Vis Spectroscopy ◽  
Oxygen Atoms

Nanocomposite (NCP) films of polycarbonate-polybutylene terephthalate (PC-PBT) blend as a host material to Cr2O3 and CdS nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Samples from the PC-PBT/Cr2O3 and PC-PBT/CdS NCPs were irradiated using different doses (20–110 kGy) of γ radiation. The induced modifications in the optical properties of the γ irradiated NCPs have been studied as a function of γ dose using UV Vis spectroscopy and CIE color difference method. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the NCP films and to identify the types of electronic transition. The value of optical band gap energy of PC-PBT/Cr2O3 NCP was reduced from 3.23 to 3.06 upon γ irradiation up to 110 kGy, while it decreased from 4.26 to 4.14 eV for PC-PBT/CdS NCP, indicating the growth of disordered phase in both NCPs. This was accompanied by a rise in the refractive index for both the PC-PBT/Cr2O3 and PC-PBT/CdS NCP films, leading to an enhancement in their isotropic nature. The Cr2O3 NPs were found to be more effective in changing the band gap energy and refractive index due to the presence of excess oxygen atoms that help with the oxygen atoms of the carbonyl group in increasing the chance of covalent bonds formation between the NPs and the PC-PBT blend. Moreover, the color intensity, ΔE has been computed; results show that both the two synthesized NCPs have a response to color alteration by γ irradiation, but the PC-PBT/Cr2O3 has a more response since the values of ΔE achieved a significant color difference >5 which is an acceptable match in commercial reproduction on printing presses. According to the resulting enhancement in the optical characteristics of the developed NCPs, they can be a suitable candidate as activate materials in optoelectronic devices, or shielding sheets for solar cells.

Stability Investigation in the Optical Properties of Thermally Evaporated Ge5Se95-x Znx Thin Films

2015 ◽  
Vol 7 (3) ◽  
pp. 1923-1930
Author(s):  
Austine Amukayia Mulama ◽  
Julius Mwakondo Mwabora ◽  
Andrew Odhiambo Oduor ◽  
Cosmas Mulwa Muiva ◽  
Boniface Muthoka ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Optical Band Gap ◽  
Thermal Evaporation ◽  
Optical Transition ◽  
Bulk Material ◽  
Band Gap Energy ◽  
Optical Absorbance ◽  
Gap Energy ◽  
Constituent Elements

 Selenium-based chalcogenides are useful in telecommunication devices like infrared optics and threshold switching devices. The investigated system of Ge5Se95-xZnx (0.0 ≤ x ≤ 4 at.%) has been prepared from high purity constituent elements. Thin films from the bulk material were deposited by vacuum thermal evaporation. Optical absorbance measurements have been performed on the as-deposited thin films using transmission spectra. The allowed optical transition was found to be indirect and the corresponding band gap energy determined. The variation of optical band gap energy with the average coordination number has also been investigated based on the chemical bonding between the constituents and the rigidity behaviour of the system’s network.

scholarly journals Polymer Thermal Treatment Production of Cerium Doped Willemite Nanoparticles: An Analysis of Structure, Energy Band Gap and Luminescence Properties

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1118
Author(s):  
Ibrahim Mustapha Alibe ◽  
Khamirul Amin Matori ◽  
Mohd Hafiz Mohd Zaid ◽  
Salisu Nasir ◽  
Ali Mustapha Alibe ◽  
...  
Keyword(s):  
Solid State ◽  
Thermal Treatment ◽  
Band Gap ◽  
Optical Band Gap ◽  
Dopant Concentration ◽  
Blue Emission ◽  
Green Emission ◽  
Band Gap Energy ◽  
Solid State Lighting ◽  
Gap Energy

The contemporary market needs for enhanced solid–state lighting devices has led to an increased demand for the production of willemite based phosphors using low-cost techniques. In this study, Ce3+ doped willemite nanoparticles were fabricated using polymer thermal treatment method. The special effects of the calcination temperatures and the dopant concentration on the structural and optical properties of the material were thoroughly studied. The XRD analysis of the samples treated at 900 °C revealed the development and or materialization of the willemite phase. The increase in the dopant concentration causes an expansion of the lattice owing to the replacement of larger Ce3+ ions for smaller Zn2+ ions. Based on the FESEM and TEM micrographs, the nanoparticles size increases with the increase in the cerium ions. The mean particles sizes were estimated to be 23.61 nm at 1 mol% to 34.02 nm at 5 mol% of the cerium dopant. The optical band gap energy of the doped samples formed at 900 °C decreased precisely by 0.21 eV (i.e., 5.21 to 5.00 eV). The PL analysis of the doped samples exhibits a strong emission at 400 nm which is ascribed to the transition of an electron from localized Ce2f state to the valence band of O2p. The energy level of the Ce3+ ions affects the willemite crystal lattice, thus causing a decrease in the intensity of the green emission at 530 nm and the blue emission at 485 nm. The wide optical band gap energy of the willemite produced is expected to pave the way for exciting innovations in solid–state lighting applications.

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