First Principles Study on Electronic and Optical Properties  of Quinary Copper-based Sulfides and Selenides  Cu2HgGe(S1-xSex)4

Electronic and optical properties of Cu2HgGe(S1-xSex)4 compounds (x = 0, 0.25, 0.5, 0.75, and 1) were revealed by density functional theory (DFT), in which the Heyd-Scuseria-Ernzerhof hybrid functional was used. Dependence of band gap on the Se constituent in Cu2HgGe(S1-xSex)4 was reported. The substitution of Se element basically cause a slightly lattice expansion and minor change of the band gap. Meanwhile, the overlap of Cu and S/Se states becomes more dense leading to better electron/hole pair separation and inter-band transition of photo-excited electrons. The Cu2HgGe(S0.75Se0.25)4 compound was predicted to be very promising absorber due to the low band gap, high absorption rate, and low reflectivity in the incoming light energy range from 0 eV to 2 eV.

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

Materials ◽

10.3390/ma11101937 ◽

2018 ◽

Vol 11 (10) ◽

pp. 1937 ◽

Cited By ~ 5

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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Structural, Electronic and Optical Properties of Nd-Doped Anatase TiO2 for Dye-Sensitized Solar Cells from Density Functional Theory

Materials Science Forum ◽

10.4028/www.scientific.net/msf.846.726 ◽

2016 ◽

Vol 846 ◽

pp. 726-733

Author(s):

Mohd Hazrie Samat ◽

N.H. Hussin ◽

Mohamad Fariz Mohamad Taib ◽

M.K. Yaakob ◽

Noor Syafiqah Samsi ◽

...

Keyword(s):

Density Functional Theory ◽

Optical Properties ◽

Band Gap ◽

First Principles ◽

Density Functional ◽

Dye Sensitized Solar Cells ◽

Functional Theory ◽

Electronic And Optical Properties ◽

Dye Sensitized ◽

Sensitized Solar Cells

The structural, electronic and optical properties of pure and neodymium (Nd) doped anatase titanium dioxide (TiO2)are investigated via first-principles calculations within density functional theory (DFT) approach. The band gap reduces to ~0.398 eV when Ti4+ is substituted with Nd3+ in TiO2 crystal structure. The presence of Nd 4f states in the conduction band of TiO2 clarifies the reducing of the band gap. The dielectric constant and refractive index of Nd-doped TiO2 increase compare to pure TiO2. Nd-doped TiO2 able to enhance light absorption to longer wavelength spectrum. The first-principles results obtained satisfy the criteria for Nd-doped TiO2 to become feasible photoanode material in dye-sensitized solar cell (DSSC) device.

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Electronic and optical properties of GaN/AlN core–shell nanowires

Modern Physics Letters B ◽

10.1142/s0217984920500219 ◽

2019 ◽

Vol 34 (02) ◽

pp. 2050021 ◽

Cited By ~ 4

Author(s):

Jiangshan Zheng ◽

Enling Li ◽

Jie Yan ◽

Zhen Cui ◽

Deming Ma

Keyword(s):

Optical Properties ◽

Band Gap ◽

Electromagnetic Waves ◽

Density Functional ◽

Field Energy ◽

Core Shell ◽

Functional Theory ◽

Electronic And Optical Properties ◽

Ultraviolet Range ◽

Shell Nanowires

The electronic and optical properties of GaN/AlN core–shell nanowires (NWs) with different core–shell ratios are studied by means of density functional theory (DFT). The results show that as the GaN core structure increases (the AlN shell remains unchanged), the band gap of NWs decreases. In contrast, with the increase of AlN shell (GaN nucleus remains unchanged), the band gap almost remains unchanged. That is to say the adjustment capability of core–shell ratio for the band gap of GaN/AlN core–shell NWs with the same diameter of GaN core degenerates, and the band gap of which are mainly controlled by GaN core. Ga–N bond and Al–N bond show a strong ionic property because of the electronegativity of N is strong over Ga and Al. In addition, the calculated results of the real part [Formula: see text] and the imaginary parts [Formula: see text] with photon energy indicate that the storage capability and loss of the NWs to electric field energy are different with the content of AlN. The four structured NWs reflect electromagnetic waves as conductor in a high frequency ultraviolet range. The results are valuable for the design of GaN/AlN core–shell NWs optoelectronic nanodevices and the research of other core–shell NWs heterostructures.

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Electronic, structural and optical properties of zincblend and wurtizite cadmium selenide (CdSe) using density functional theory and hubbard correction

Фізика і хімія твердого тіла ◽

10.15330/pcss.22.1.16-23 ◽

2021 ◽

Vol 22 (1) ◽

pp. 16-23

Author(s):

Teshome Gerbaba Edossa ◽

Menberu Woldemariam

Keyword(s):

Density Functional Theory ◽

Optical Properties ◽

Total Energy ◽

Band Gap ◽

Cadmium Selenide ◽

Density Functional ◽

Hybrid Functional ◽

Functional Theory ◽

Functional Approximation ◽

Exchange Correlation

Zinc blend (zb) and wurtizite (wz) structure of cadmium selenide (CdSe) is determined using density-functional theory within local density approximation (LDA), generalized gradient approximation (GGA), Hubbard-correction (GGA+U) and Hybrid functional approximation (PBE0 or HSE06). The first principle pseudopotential plane wave is used and the relaxed atomic position for the CdSe in zb and wz structure was obtained by using total energy and force minimization method following the Hellmann Feynman approach. The convergence test of total energy with respect to cutoff energy and k-point sampling is performed . The equilibrium lattice constant and unit cell volume of CdSe in both phases are calculated and the obtained value is compared` with experimental values. In addition the band gap of CdSe is analyzed using DFT within LDA, GGA, DFT+U and PBE0 to approximate the unknown exchange correlation functional. The band gap values obtained using LDA and GGA are severally under estimated due to their poor approximation of exchange-correlation potential. This problem was improved by using projector augmented-wave pseudopotential within Hubbard-correction (GGA+U) and the hybrid functional approximation. Optical properties: complex and real parts of dielectric function, energy loss spectrum and absorption coefficient of CdSe in both ZB and WZ phase were studied.

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Influence on structural, electronic and optical properties of Fe doped ZnS quantum dot: A density functional theory based study

International Journal of Quantum Chemistry ◽

10.1002/qua.26786 ◽

2021 ◽

Author(s):

Md. Abdul Momin ◽

Md. Aminul Islam ◽

Abhijit Majumdar

Keyword(s):

Density Functional Theory ◽

Optical Properties ◽

Quantum Dot ◽

Density Functional ◽

Functional Theory ◽

Electronic And Optical Properties

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Electronic and optical properties of vacancy ordered double perovskites A2BX6 (A = Rb, Cs; B = Sn, Pd, Pt; and X = Cl, Br, I): a first principles study

Scientific Reports ◽

10.1038/s41598-021-86145-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Muhammad Faizan ◽

K. C. Bhamu ◽

Ghulam Murtaza ◽

Xin He ◽

Neeraj Kulhari ◽

...

Keyword(s):

Optical Properties ◽

Band Gap ◽

First Principles ◽

Density Functional ◽

Perovskite Solar Cells ◽

Dielectric Constants ◽

Maximum Efficiency ◽

Exchange Potential ◽

Double Perovskites ◽

Electronic And Optical Properties

AbstractThe highly successful PBE functional and the modified Becke–Johnson exchange potential were used to calculate the structural, electronic, and optical properties of the vacancy-ordered double perovskites A2BX6 (A = Rb, Cs; B = Sn, Pd, Pt; X = Cl, Br, and I) using the density functional theory, a first principles approach. The convex hull approach was used to check the thermodynamic stability of the compounds. The calculated parameters (lattice constants, band gap, and bond lengths) are in tune with the available experimental and theoretical results. The compounds, Rb2PdBr6 and Cs2PtI6, exhibit band gaps within the optimal range of 0.9–1.6 eV, required for the single-junction photovoltaic applications. The photovoltaic efficiency of the studied materials was assessed using the spectroscopic-limited-maximum-efficiency (SLME) metric as well as the optical properties. The ideal band gap, high dielectric constants, and optimum light absorption of these perovskites make them suitable for high performance single and multi-junction perovskite solar cells.

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