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.

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 Ni Oxidation State and Ligand Saturation Impact on the Capability of Octaazamacrocyclic Complexes to Bind and Reduce CO2

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4139
Author(s):  
Barbora Vénosová ◽  
Ingrid Jelemenská ◽  
Jozef Kožíšek ◽  
Peter Rapta ◽  
Michal Zalibera ◽  
...  
Keyword(s):  
Quantum Theory ◽  
Oxidation State ◽  
Central Atom ◽  
Population Analysis ◽  
Mulliken Population Analysis ◽  
Mulliken Population ◽  
Theoretical Methods ◽  
Ni Oxidation ◽  
Shed Light

Two 15-membered octaazamacrocyclic nickel(II) complexes are investigated by theoretical methods to shed light on their affinity forwards binding and reducing CO2. In the first complex 1[NiIIL]0, the octaazamacrocyclic ligand is grossly unsaturated (π-conjugated), while in the second 1[NiIILH]2+ one, the macrocycle is saturated with hydrogens. One and two-electron reductions are described using Mulliken population analysis, quantum theory of atoms in molecules, localized orbitals, and domain averaged fermi holes, including the characterization of the Ni-CCO2 bond and the oxidation state of the central Ni atom. It was found that in the [NiLH] complex, the central atom is reduced to Ni0 and/or NiI and is thus able to bind CO2 via a single σ bond. In addition, the two-electron reduced 3[NiL]2− species also shows an affinity forwards CO2.

Molecular Calculations of Interplanar Electronic Interactions in a Ybacu2O6+δ Cluster as a Function of the Oxygen Concentration.

1990 ◽  
Vol 209 ◽  
Author(s):  
J. A. Cogordan ◽  
L. E. Sansores ◽  
A. A. Valladares
Keyword(s):  
Charge Transfer ◽  
Ab Initio ◽  
Population Analysis ◽  
Oxygen Stoichiometry ◽  
Mulliken Population Analysis ◽  
Mulliken Population ◽  
Electronic Interactions ◽  
A Charge ◽  
Molecular Calculations ◽  
Scf Calculations

ABSTRACTMolecular ab initio SCF calculations on a cluster formed by Y, Cu(2)-O(2)-O(3) plane, Ba-O(1) plane and Cu(1)-O(4) chains are reported. The computations were performed for five different sets of lattice parameters of YBACu2O6+δ Each of these sets correspond to a values of the oxygen stoichiometry. Mulliken population analysis results show a charge transfer to the Cu(2)-O(2)-O(3) plane when the oxygen stoichiometry is increased from six to seven.

Orientation Effects of CH3NH3+ on CH3NH3PbI3 Stability and Photoelectric Properties

2016 ◽  
Vol 850 ◽  
pp. 245-252 ◽  
Author(s):  
Jun Zhou ◽  
Fu Ling Tang ◽  
Hong Tao Xue ◽  
Feng Juan Si
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
First Principles ◽  
First Principles Calculations ◽  
Photoelectric Properties ◽  
Orientation Effects ◽  
Light Absorber ◽  
Absorber Material ◽  
Organic Functional Groups ◽  
The Stability

The orientation effects of the organic functional groups CH3NH3+ along [100], [110], [111] and [210] on the stability and photoelectric properties of CH3NH3PbI3 were investigated using first-principles calculations. The results showed that the system energies when C-N bond was along [100]/[210] directions were lower than those while C-N bond was along [110]/[111] directions. The band gap while C-N bond was along [100]/[210] direction was larger than that while C-N bond was along [110]/111] direction. The system energy changed within the range of 0.8 eV, and the band gap changed within the range of 0.05 eV as CH3NH3+ moving along the same crystal direction. The optical properties of CH3NH3PbI3 with the C-N bond along [100] direction were different from those with the C-N bond along [111] direction, while the differences were not obvious. The change trends of optical properties with CH3NH3+ moving for two structures were in agreement with each other. The optical properties indicate that CH3NH3PbI3 is a good light absorber material for thin film solar cells.

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