scholarly journals The electronic structure and optical properties of Ca3(Mn1−xTix)2O7from first-principle calculations

2019 ◽  
Vol 09 (01) ◽  
pp. 1950007
Author(s):  
Fengqi Wang ◽  
Wei Cai ◽  
Chunlin Fu ◽  
Rongli Gao ◽  
Gang Chen ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Band Gap ◽  
Population Analysis ◽  
Covalent Bond ◽  
Index Formula ◽  
First Principle ◽  
Mulliken Population ◽  
First Principle Calculations ◽  
Text Content

The electronic structure and optical properties of Ca3(Mn[Formula: see text]Ti[Formula: see text]O7 ([Formula: see text], 1/8, 2/8, 3/8, 4/8) were studied by first-principle calculations within the generalized gradient approximation approaches (GGA). The lattice constants of Ca3(Mn[Formula: see text]Ti[Formula: see text]O7 increase with the increase of Ti[Formula: see text] content caused by the substitution of Ti[Formula: see text] with larger ionic radius for Mn[Formula: see text]. Ca3(Mn[Formula: see text]Ti[Formula: see text]O7 is a direct band gap semiconductor, and the band gap ([Formula: see text]) increases with the increase of Ti[Formula: see text] content. From the density of states, the introduction of Ti-3[Formula: see text] states can weaken the effects of Mn-3[Formula: see text] states on the bottom of conduction band and has little influence on O-2[Formula: see text] states on the top of valence band. The introduction of nonmagnetic Ti[Formula: see text] ions can weaken the magnetism of Ca3(Mn[Formula: see text]Ti[Formula: see text]O7. According to the Mulliken population analysis, it is found that the introduction of Ti[Formula: see text] enhances the electronic accepting capacity of oxygen ions and enhances the electronic losing capacity of manganese ions. The bond strength of Ti–O covalent bond is stronger than that of Mn–O covalent bond. Furthermore, the optical properties of Ca3(Mn[Formula: see text]Ti[Formula: see text]O7 was calculated. As Ti[Formula: see text] content increases, the absorption edge of Ca3(Mn[Formula: see text]Ti[Formula: see text]O7 has a blue shift, the static refractive index [Formula: see text] decreases, the static dielectric constant [Formula: see text](0) decreases, the position of loss peak moves to higher energy.

scholarly journals Effect of Doping on the Photoelectric Properties of Borophene

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Chunhong Zhang ◽  
Zhongzheng Zhang ◽  
Wanjun Yan ◽  
Xinmao Qin
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Population Analysis ◽  
Covalent Bond ◽  
Infrared Light ◽  
Chemical Bonds ◽  
Mulliken Population Analysis ◽  
Mulliken Population ◽  
Photoelectric Properties ◽  
Effect Of Doping

Borophene is a new type of two-dimensional material with a series of unique and diversified properties. However, most of the research is still in its infancy and has not been studied in depth. Especially in the field of semiconductor optoelectronics, there is no related research on the modulation of photoelectric properties of borophene. In this work, we focus on the effect of doping on the photoelectric properties of borophene by using the first-principles pseudopotential plane wave method. We calculate the geometric structure, electronic structure, Mulliken population analysis, and optical properties of impurity (X = Al, Ga) doped α-sheet borophene. The results show that α-sheet borophene is an indirect band gap semiconductor with 1.396 eV. The band gap becomes wider after Al and Ga doping, and the band gap values are 1.437 eV and 1.422 eV, respectively. Due to the orbital hybridization between a small number of Al-3p electrons and Ga-4p state electrons and a large number of B 2p state electrons near the Fermi level, the band gap of borophene changes and the peak value of the electron density of states reduces after doping. Mulliken population analysis shows that the B0-B bond is mainly covalent bond, but there is also a small amount of ionic bond. However, when the impurity X is doped, the charge transfer between X and B atoms increases significantly, and the population of the corresponding X-B bonds decreases, indicating that the covalent bond strength of the chemical bonds in the doped system is weakened, and the chemical bonds have significant directionality. The calculation of optical properties shows that the static dielectric constant of the borophene material increases, and the appearance of a new dielectric peak indicates that the doping of Al and Ga can enhance the ability of borophene to store electromagnetic energy. After doping, the peak reflectivity decreases and the static refractive index n0 increases, which also fills the gap in the absorption of red light and infrared light by borophene materials. The research results provide a basis for the development of borophene materials in the field of infrared detection devices. The above results indicate that doping can modulate the photoelectric properties of α-sheet borophene.

Electronic structure and optical properties of Fe-doped SnS2 from first-principle calculations

RSC Advances ◽  
2016 ◽  
Vol 6 (5) ◽  
pp. 3480-3486 ◽  
Author(s):  
Lili Sun ◽  
Wei Zhou ◽  
Yanyu Liu ◽  
Dandan Yu ◽  
Yinghua Liang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Infrared Region ◽  
First Principle ◽  
Fe Doping ◽  
Visible Absorption ◽  
First Principle Calculations

The Fe doping can increase the visible absorption of SnS2 and extend the absorption into the infrared region.

scholarly journals Theoretical and experimental study on the electronic and optical properties of K0.5Rb0.5Pb2Br5: a promising laser host material

RSC Advances ◽  
2020 ◽  
Vol 10 (19) ◽  
pp. 11156-11164 ◽  
Author(s):  
Tuan V. Vu ◽  
A. A. Lavrentyev ◽  
B. V. Gabrelian ◽  
Dat D. Vo ◽  
Hien D. Tong ◽  
...  
Keyword(s):  
Experimental Study ◽  
Optical Properties ◽  
Electronic Structure ◽  
Host Material ◽  
First Principle ◽  
X Ray ◽  
Electronic And Optical Properties ◽  
First Principle Calculations

The data on the electronic structure and optical properties of bromide K0.5Rb0.5Pb2Br5 achieved by first-principle calculations and verified by X-ray spectroscopy measurements are reported.

Electronic Structure Analyses of BN in Cubic and Hexagonal Phases

2011 ◽  
Vol 268-270 ◽  
pp. 1-3
Author(s):  
Ting Zhang ◽  
Ming He ◽  
Tao Chen ◽  
Guang Chang Wang
Keyword(s):  
Electronic Structure ◽  
Dielectric Properties ◽  
Plane Wave ◽  
Band Gap ◽  
Energy Band ◽  
First Principle ◽  
Energy Band Gap ◽  
First Principle Calculations ◽  
Two Phases ◽  
Valence Band Width

First principle calculations are performed on the structure, energy band gap, and dielectric properties of wurtzite and hexagonal BN by using a plane-wave pseudopotential method. It is found thath-BN has much narrower VB (valence band ) width and much sharper band edge than those ofw-BN. And the N 2sstates of the two phases of BN are dominant below 30.03 eV and the N 2pstates are dominant in the range between −20.62 and 20.32 eV.

Electronic Structures and Optical Properties of CuIn1-XGaXSe2 by First-Principle Calculations

2011 ◽  
Vol 239-242 ◽  
pp. 1304-1308
Author(s):  
Zong Bao Li
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Electronic Structures ◽  
First Principle ◽  
Quaternary Compound ◽  
Double Peak Structure ◽  
First Principle Calculations ◽  
Peak Structure ◽  
Small Band ◽  
Different Content

First-principle calculations on the electronic structures and optical properties of CuIn1-xGaxSe2(x=0, 0.25, 0.5, 0.75 and 1) reveal that CuIn1-xGaxSe2are small band gap materials and the ground state is stabiles from x=0 to 1 while the band-gap of the quaternary compound widen, all of that are in good agreement with the experimental results. We find that the obviously double peak structure of the imaginary of dielectric function centered about from 0.9 to 5.0 while a distinct peak appears at about 2.2eV and a smooth increasing with another peak appearing at about 5.5eV for the different content of Ga appearing in the absorption spectrum, all of which indicate the different band gap for the transition.

scholarly journals First-principles Calculation of the Electronic Structure and Optical Properties of ZnO Co-doped with Nb and Ta

2019 ◽  
Vol 25 (3) ◽  
pp. 238-245 ◽  
Author(s):  
Jinpeng WANG ◽  
Tao SHEN ◽  
Hongchen LIU
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
First Principles Calculation ◽  
Ultraviolet Region ◽  
First Principle ◽  
Co Doping ◽  
First Principle Calculations ◽  
Function Loss ◽  
Co Doped

First-principle calculations have been performed to investigate the electronic structure and optical properties of ZnO co-doped with Nb and Ta. The three doping structures are set to: Zn0.9375Nb0.0625O, Zn0.9375Ta0.0625O and Zn0.875Nb0.0625Ta0.0625O. The experiments show that co-doping with Nb and Ta narrows the band gap. And it causes the Fermi level to shift upwards and enter the conduction band, while enhancing the conductivity of the doped system. In addition, it has been determined that the dielectric imaginary part of the dopant system is larger than that of the pure ZnO in the low energy region. The absorption side of the dopant system, on the other hand, exhibits a redshift. Furthermore, the transmittance of the ultraviolet region is significantly increased, and the function loss spectrum appears to redshift. This will provide a good theoretical basis for the study and the applications of photoelectric materials co-doped with Nb and Ta. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.19956

Electronic Structure and Optical Properties of SiC Nanotube Material with Silicon Antisite Defect

2012 ◽  
Vol 625 ◽  
pp. 230-234
Author(s):  
Ke Jian Li ◽  
Jiu Xu Song ◽  
Hong Xia Liu
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Conduction Band ◽  
Antisite Defect ◽  
Optical Devices ◽  
First Principle ◽  
Defect Level ◽  
First Principle Calculations ◽  
Dielectric Peak ◽  
Sic Nanotube

Based on first-principle calculations, electronic structure and optical properties of a single-walled zigzag SiC nanotube with silicon antisite defect have been investigated. This defect results in the formation of a bump in the surface of the nanotube. No defect energy level is formed in its band gap, which is originated from the resonance between the defect level and conduction band resulting in the defect level entering its conduction band. The most primary dielectric peak in dielectric function parallel to the axis of the nanotube is depressed, while the first peak perpendicular to its axis is enhanced. These results are meaningful for investigations on SiCNT electronic and optical devices.

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