scholarly journals Diverse Role of Silicon Carbide in the Domain of Nanomaterials

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
T. Sahu ◽  
B. Ghosh ◽  
S. K. Pradhan ◽  
T. Ganguly
Keyword(s):  
Silicon Carbide ◽  
Optical Properties ◽  
Band Gap ◽  
High Performance ◽  
Theoretical Work ◽  
Optical Devices ◽  
Unique Property ◽  
Promising Material ◽  
Indirect Band Gap

Silicon carbide (SiC) is a promising material due to its unique property to adopt different crystalline polytypes which monitor the band gap and the electronic and optical properties. Despite being an indirect band gap semiconductor, SiC is used in several high-performance electronic and optical devices. SiC has been long recognized as one of the best biocompatible materials, especially in cardiovascular and blood-contacting implants and biomedical devices. In this paper, diverse role of SiC in its nanostructured form has been discussed. It is felt that further experimental and theoretical work would help to better understanding of the various properties of these nanostructures in order to realize their full potentials.

scholarly journals Tunable relativistic quasiparticle electronic and excitonic behavior of the FAPb(I1−xBrx)3 alloy

2020 ◽  
Vol 22 (21) ◽  
pp. 11943-11955 ◽  
Author(s):  
Zeeshan Muhammad ◽  
Peitao Liu ◽  
Rashid Ahmad ◽  
Saeid Jalali Asadabadi ◽  
Cesare Franchini ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
Band Gap ◽  
High Performance ◽  
Material Design ◽  
Tandem Solar Cells ◽  
Excitonic Properties

The quasiparticle and excitonic properties of mixed FAPb(I1−xBrx)3 0 ≤ x ≤ 1 alloys are studied. We show that Br-doping provides an efficient and controllable way to tune the band gap and optical properties, beneficial for material design of high performance tandem solar cells.

SHIFT OF BAND GAP FROM DIRECT TO INDIRECT AND OPTICAL RESPONSE OF LiF UNDER PRESSURE

2013 ◽  
Vol 27 (09) ◽  
pp. 1350061 ◽  
Author(s):  
A. SAJID ◽  
G. MURTAZA ◽  
A. H. RESHAK
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Lithium Fluoride ◽  
Pressure Range ◽  
Pressure Effect ◽  
Indirect Transition ◽  
Direct Band Gap ◽  
Direct Band ◽  
Indirect Band Gap

We hereby are reporting the transition pressure at which lithium fluoride ( LiF ) compound transforms from direct band gap to indirect band gap insulator on the basis of FP-LAPW calculations. The fundamental band gap of LiF compound suffers direct to indirect transition at a pressure of 70 GPa. The study of the pressure effect on the optical properties e.g. dielectric function, reflectivity, refractive index and optical conductivity of LiF in the pressure between 0–100 GPa, shows that this pressure range is very critical for LiF compound as there are significant changes in the optical properties of this compound.

Electronic structures and optical properties of cuprous oxide and hydroxide

2014 ◽  
Vol 1675 ◽  
pp. 185-190
Author(s):  
Yunguo Li ◽  
Cláudio M. Lousada ◽  
Pavel A. Korzhavyi
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Cuprous Oxide ◽  
Density Functional ◽  
Spent Nuclear Fuel ◽  
Energy Levels ◽  
Chemical Properties ◽  
Density Functional Theory Calculations ◽  
Hybrid Functional ◽  
Indirect Band Gap

ABSTRACTThe broad range of applications of copper, including areas such as electronics, fuel cells, and spent nuclear fuel disposal, require accurate description of the physical and chemical properties of copper compounds. Within some of these applications, cuprous hydroxide is a compound whose relevance has been recently discovered. Its existence in the solid-state form was recently reported. Experimental determination of its physical-chemical properties is challenging due to its instability and poop crystallinity. Within the framework of density functional theory calculations (DFT), we investigated the nature of bonding, electronic spectra, and optical properties of the cuprous oxide and cuprous hydroxide. It is found that the hybrid functional PBE0 can accurately describe the electronic structure and optical properties of these two copper(I) compounds. The calculated properties of cuprous oxide are in good agreement with the experimental data and other theoretical results. The structure of cuprous hydroxide can be deduced from that of cuprous oxide by substituting half Cu+ in Cu2O lattice with protons. Compared to Cu2O, the presence of hydrogen in CuOH has little effect on the ionic nature of Cu–O bonding, but lowers the energy levels of the occupied states. Thus, CuOH is calculated to have a wider indirect band gap of 2.73 eV compared with the Cu2O band gap of 2.17 eV.

scholarly journals Structural and Optical Properties of Sm3+ Doped B-site Ba0.5Rb0.5LaTeO6 Double Perovskites

2019 ◽  
Vol 8 (4) ◽  
pp. 6735-6739
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Solid State Reaction Method ◽  
Tolerance Factor ◽  
Double Perovskites ◽  
Structural And Optical Properties ◽  
Visible Absorption ◽  
Cubic Symmetry ◽  
Uv Visible ◽  
Indirect Band Gap

A double perovskites Ba0.5Rb0.5LaTeO6 and Ba0.5Rb0.5La0.9Sm0.1TeO6 were synthesized by a solid-state reaction method. The structural properties were studied by using the X-Ray powder diffraction (XRD) and fourier transform infrared spectroscopy (FTIR). Structural analysis of XRD based on Rietveld refinement indicates that the Ba0.5Rb0.5LaTeO6 and Ba0.5Rb0.5La0.9Sm0.1TeO6 have cubic symmetry with space group Fm m. The tolerance factor of the sample also decreases with Sm3+ substitution. The value obtained from tolerance factor for Ba0.5Rb0.5LaTeO6 and Ba0.5Rb0.5La0.9Sm0.1TeO6 was 0.994 and 0.982 respectively. The optical properties were studied using the UV visible absorption spectroscopy (UV-vis). The Ba0.5Rb0.5LaTeO6 and Ba0.5Rb0.5La0.9Sm0.1TeO6 was assumed to be indirect band gap and the optical band gap obtained for Ba0.5Rb0.5LaTeO6 and Ba0.5Rb0.5La0.9Sm0.1TeO6 were 4.1 eV and 4.3 eV respectively

Electronic structures and optical properties of IV A elements-doped 3C-SiC from density functional calculations

2018 ◽  
Vol 32 (32) ◽  
pp. 1850389 ◽  
Author(s):  
Xuefeng Lu ◽  
Tingting Zhao ◽  
Xin Guo ◽  
Meng Chen ◽  
Junqiang Ren ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Electronic Structures ◽  
Density Functional ◽  
Visible Region ◽  
First Principles Calculation ◽  
Charge Difference Density ◽  
Direct Band ◽  
Density Analysis ◽  
Indirect Band Gap

Electronic structures and optical properties of IV A elements (Ge, Sn and Pb)-doped 3C-SiC are investigated by means of the first-principles calculation. The results reveal that the structure of Ge-doped system is more stable with a lower formation energy of 1.249 eV compared with those of Sn- and Pb-doped 3C-SiC systems of 3.360 eV and 5.476 eV, respectively. Doping of the IV A elements can increase the band gap, and there is an obvious transition from an indirect band gap to a direct band gap. Furthermore, charge difference density analysis proves that the covalent order of bonding between the doping atoms and the C atoms is Ge–C [Formula: see text] Sn–C [Formula: see text] Pb–C, which is fully verified by population values. Due to the lower static dielectric constant, the service life of 3C-SiC dramatically improved in production practice. Moreover, the lower reflectivity and absorption peak in the visible region, implying its wide application foreground in photoelectric devices.

Electronic and optical properties of CsPb2Br5: A first-principles study

2019 ◽  
Vol 33 (22) ◽  
pp. 1950266 ◽  
Author(s):  
Mingge Jin ◽  
Zhibing Li ◽  
Feng Huang ◽  
Weiliang Wang
Keyword(s):  
Optical Properties ◽  
Optical Absorption ◽  
Visible Light ◽  
Band Gap ◽  
First Principles ◽  
First Principles Calculations ◽  
Hybrid Functional ◽  
Electronic And Optical Properties ◽  
Optical Absorbance ◽  
Indirect Band Gap

There are conflicting understandings of the electronic and optical properties of CsPb2Br5. We investigated the electronic and optical properties of CsPb2Br5 with first-principles calculations. It is confirmed that CsPb2Br5 is a semiconductor with an indirect band gap of 3.08 eV at GGA/PBE level and 3.72 eV at the HSE06 hybrid functional level. The PBE results demonstrate that the inclusion of SOC slightly reduces the band gap. We calculate the optical absorbance/emission spectrum of CsPb2Br5. It is found the optical absorption edges locate at 360–380 nm, shorter than the wavelength of visible light. Our results support the experimental results of Li et al. [Chem. Commun. 52 (2016) 11296] and Zhang et al. [J. Mater. Chem. C 6 (2018) 446].

Role of microstructure on optical properties in high-uniformity In1−xGaxAs nanowire arrays: Evidence of a wider wurtzite band gap

2013 ◽  
Vol 87 (20) ◽  
Author(s):  
Stefanie Morkötter ◽  
Stefan Funk ◽  
Mengyu Liang ◽  
Markus Döblinger ◽  
Simon Hertenberger ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Nanowire Arrays ◽  
High Uniformity

scholarly journals Optical quantum confinement and photocatalytic properties in two-, one- and zero-dimensional nanostructures

2018 ◽  
Vol 5 (9) ◽  
pp. 180387 ◽  
Author(s):  
T. Edvinsson
Keyword(s):  
Band Gap ◽  
High Performance ◽  
New Physics ◽  
Photocatalytic Properties ◽  
Carrier Confinement ◽  
Surface Areas ◽  
Low Dimensionality ◽  
Direct Band ◽  
Indirect Band Gap ◽  
Low Dimensional

Low-dimensional nanomaterials have been explored extensively in the last decades, partly fuelled by the new possibilities for tuning and controlling their electronic properties. In a broader perspective within catalysis, two-, one- and zero-dimensional (2D, 1D and 0D) inorganic nanomaterials represent a bridge between the selectivity of molecular catalysts and the high performance and stability of inorganic catalysts. As a consequence of the low dimensions, higher surface areas are obtained but also introduce new physics and increased tuneability of the electronic states in the nanostructured system. Herein, we derive the commonly used equations for optical transitions and carrier confinement in semiconductors and discuss their effect on the optical and photocatalytic properties of direct band and indirect band gap materials. In particular, the physical properties of the optical and photocatalytic properties of Fe 2 O 3 and ZnO will be used to exemplify the effects of the low dimensionality. Carrier confinement effects with changes in the density of states, band gap/shift of band edges will be outlined together with their effects on the tuneability of the material and their wider application as photocatalytic materials.

scholarly journals Stable GaSe-Like Phosphorus Carbide Monolayer with Tunable Electronic and Optical Properties from Ab Initio Calculations

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1937 ◽  
Author(s):  
Xiaolin Cai ◽  
Zhili Zhu ◽  
Weiyang Yu ◽  
Chunyao Niu ◽  
Jianjun Wang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Electronic Structures ◽  
Density Functional ◽  
Promising Candidate ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
Direct Band Gap ◽  
Direct Band ◽  
Indirect Band Gap

On the basis of density functional theory (DFT) calculations, we propose a stable two-dimensional (2D) monolayer phosphorus carbide (PC) with a GaSe-like structure, which has intriguing electronic and optical properties. Our calculated results show that this 2D monolayer structure is more stable than the other allotropes predicted by Tománek et al. [Nano Lett., 2016, 16, 3247–3252]. More importantly, this structure exhibits superb optical absorption, which can be mainly attributed to its direct band gap of 2.65 eV. The band edge alignments indicate that the 2D PC monolayer structure can be a promising candidate for photocatalytic water splitting. Furthermore, we found that strain is an effective method used to tune the electronic structures varying from direct to indirect band-gap semiconductor or even to metal. In addition, the introduction of one carbon vacancy in such a 2D PC structure can induce a magnetic moment of 1.22 µB. Our findings add a new member to the 2D material family and provide a promising candidate for optoelectronic devices in the future.

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