scholarly journals Structural, Electronic, and Optical Properties of Group 6 Doped Anatase TiO2: A Theoretical Approach

2021 ◽  
Vol 11 (4) ◽  
pp. 1657
Author(s):  
Petros-Panagis Filippatos ◽  
Nikolaos Kelaidis ◽  
Maria Vasilopoulou ◽  
Dimitris Davazoglou ◽  
Alexander Chroneos
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
Electron Transport ◽  
Density Functional ◽  
Perovskite Solar Cells ◽  
Solar Spectrum ◽  
Type Conductivity ◽  
Electronic And Optical Properties ◽  
Group 6 ◽  
Visible Wavelengths

Titania (TiO2) is a key material used as an electron transport in dye-sensitized and halide perovskite solar cells due to its intrinsic n-type conductivity, visible transparency, low-toxicity, and abundance. Moreover, it exhibits pronounced photocatalytic properties in the ultra-violet part of the solar spectrum. However, its wide bandgap (around 3.2 eV) reduces its photocatalytic activity in the visible wavelengths’ region and electron transport ability. One of the most efficient strategies to simultaneously decrease its bandgap value and increase its n-type conductivity is doping with appropriate elements. Here, we have investigated using the density functional theory (DFT), as well as the influence of chromium (Cr), molybdenum (Mo), and tungsten (W) doping on the structural, electronic, and optical properties of TiO2. We find that doping with group 6 elements positively impacts the above-mentioned properties and should be considered an appropriate method for photocatalystic applications. In addition to the pronounced reduction in the bandgap values, we also predict the formation of energy states inside the forbidden gap, in all the cases. These states are highly desirable for photocatalytic applications as they induce low energy transitions, thus increasing the oxide’s absorption within the visible. Still, they can be detrimental to solar cells’ performance, as they constitute trap sites for photogenerated charge carriers.

A comparative study of structural, electronic and optical properties based on metal-doped methylammonium lead halidesviafirst-principles calculations

2019 ◽  
Vol 43 (24) ◽  
pp. 9453-9457 ◽  
Author(s):  
Diwen Liu ◽  
Huijuan Jing ◽  
Rongjian Sa ◽  
Kechen Wu
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Solar Cells ◽  
Comparative Study ◽  
Density Functional ◽  
Perovskite Solar Cells ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
Metal Doped

To reduce the toxicity of Pb in perovskite solar cells, the structural stabilities, and electronic and optical properties of the mixed perovskites MAPb0.75B0.25I3(B = Mg, Ca, Sr, and Ba) were predicted using density functional theory.

scholarly journals 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

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.

scholarly journals First-Principles Studies on Structural, Electronic and Optical Properties of Fe-doped Nis2 Counter Electrode for Dye-Sensitized Solar Cells using Dft+U

2020 ◽  
Vol 17 (2) ◽  
pp. 81
Author(s):  
Nur Aisyah Ab Malik Marwan ◽  
Nurakma Natasya Md Jahangir Alam ◽  
Mohd Hazrie Samat ◽  
Muhammad Zamir Mohyedin ◽  
Nur Hafiz Hussin ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
First Principles ◽  
Density Functional ◽  
Counter Electrode ◽  
Dye Sensitized Solar Cells ◽  
Dft Method ◽  
Electronic And Optical Properties ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

The structural, electronic and optical properties of nickel disulfide (NiS2) and iron (Fe)-doped NiS2 were computed by using first-principles calculations through the density functional theory (DFT) method. The Fe was used as a dopant element to understand the behavior and the key mechanism of Fe-doped NiS2 as a counter electrode in dye-sensitized solar cells (DSSC). The results indicated that the structural properties of the NiS2 as the cubic crystal structure with the space group Pa3 (205) (pyrite structure type) agree with experimental data. The density of states (DOS) of NiS2 and Fe-doped NiS2 shows a gapless bandgap due to Mott insulator behavior. As for optical properties, the optical absorption of NiS2 is shifted towards the infrared (IR) region when doping with Fe while the conductivity of Fe-doped NiS2 is slightly higher in conductivity. These optical properties show that Fe-doped NiS2 is good for photocatalytic activity and may provide an excellent electron charge transfer for a counter electrode in DSSC

scholarly journals Density Functional Theory (DFT) Study of Electronic and Optical Properties of Donor (D)- Acceptor (A) Monomers Based on 2,7-Carbazole Linked with Some Acceptor Groups

2021 ◽  
Vol 33 (9) ◽  
pp. 2073-2081
Author(s):  
Charitha Annam ◽  
N. Murali Krishna ◽  
Mannam Subbarao
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Open Circuit ◽  
Optoelectronic Properties ◽  
Basis Set ◽  
Bandgap Energy ◽  
Electronic And Optical Properties ◽  
Solvent Phase

In present study, a progression of low bandgap carbazole molecules was developed and rendered to increase their performance for organic solar cells. Thus, a design of D-A monomers from 2,7-carbazole donors (D) and a few acceptors (A) based D-A monomers was attempted. The calculation of the electronic and optical properties of the D-A monomers considered was based on the techniques of DFT and TD-DFT at the level of B3LYP with a basis set of 6-31G (d) in the gas and chlorobenzene. The HOMO and LUMO orbital energies, the bandgap energy (Eg), and the open-circuit voltage (VOC) were calculated in the gas and solvent phase. The impacts of the acceptor groups on the calculations and optoelectronic properties of these D-A monomers are discussed in the study of the link between the electronic structure and the optoelectronic properties. Some of these D-A monomers suggested that the after-effects of this work are a good possibility for formation of organic solar cells.

scholarly journals Investigation of Structural and Optoelectronic Properties of N-Doped Hexagonal Phases of TiO2 (TiO2-xNx) Nanoparticles with DFT Realization: OPTIMIZATION of the Band Gap and Optical Properties for Visible-Light Absorption and Photovoltaic Applications

2021 ◽  
Vol 12 (3) ◽  
pp. 3836-3848
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
Visible Light ◽  
Density Functional ◽  
Visible Region ◽  
Absorption Capacity ◽  
Optical Parameters ◽  
Effective Electron ◽  
Doped Tio2 ◽  
Electronic And Optical Properties

The geometric structure, electronic and optical properties of N-doped TiO2 (TiO2-xNx) were studied within the framework of density functional theory. The effective electron-electron exchange-correlation functional and the modified Becke–Johnson potential were used to calculate electronic and optical properties. The calculated optical parameters and the density of electronic states indicate that the TiO2-xNx (0.06 ≤ x ≤ 0.25) system has a property favorable for application in solar cells. The calculated structural characteristics show that the size of these systems increases with the increasing concentration of additives. The electronic properties of N-doped TiO2 show that the bandgaps tend to decrease, and some 2p states of N atoms are located inside the bandgap, which leads to a decrease in the photon energy of the transition and absorption of visible light. As a result, the bandgap effectively decreases with doping concentration increase, while the absorption is effectively improved due to the extended absorption range, both ultraviolet, visible, and infrared range of light emission. It was found that the optimal concentration of nitrogen doping (12.5 at.%) noticeably increases the absorption capacity; hence, the conversion efficiency of TiO2 in the visible region of radiation and effectively reduces the bandgap from 3.2 to 2.4 eV. However, any further increase in concentration does not lead to an additional improvement of the absorption capacity despite the change in the bandgap, which is in good agreement with the existing experimental data. These superior characteristics make N-doped TiO2 a promising material for low-cost, high-efficiency solar cells for the mass market.

First principles calculation of structural, electronic and optical properties of (001) and (110) growth axis (InN)/(GaN)n superlattices

2021 ◽  
Vol 67 (1 Jan-Feb) ◽  
pp. 7
Author(s):  
B. Bachir Bouiadjra ◽  
N. Mehnane ◽  
N. Oukli
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Scale Up ◽  
Energy Scale ◽  
First Principles Calculation ◽  
Full Potential ◽  
Electronic Band ◽  
Electronic And Optical Properties ◽  
Growth Axis

Based on the full potential linear muffin-tin orbitals (FPLMTO) calculation within density functional theory, we systematically investigate the electronic and optical properties of (100) and (110)-oriented (InN)/(GaN)n zinc-blende superlattice with one InN monolayer and with different numbers of GaN monolayers. Specifically, the electronic band structure calculations and their related features, like the absorption coefficient and refractive index of these systems are computed over a wide photon energy scale up to 20 eV. The effect of periodicity layer numbers n on the band gaps and the optical activity of (InN)/(GaN)n SLs in the both  growth axis (001) and (110) are examined and compared. Because of prospective optical aspects of (InN)/(GaN)n such as light-emitting applications, this theoretical study can help the experimental measurements.

scholarly journals Ultrathin and compact electron transport layer made from novel water-dispersed Fe3O4 nanoparticles to accomplish UV-stable perovskite solar cells

2021 ◽  
Author(s):  
Song Fang ◽  
Bo Chen ◽  
Bangkai Gu ◽  
Linxing Meng ◽  
Hao Lu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Electron Transport ◽  
Perovskite Solar Cells ◽  
Perovskite Solar Cell ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Perovskite Material ◽  
Main Factors ◽  
Induced Decomposition

UV induced decomposition of perovskite material is one of main factors to severely destroy perovskite solar cells for instability. Here we report a UV stable perovskite solar cell with a...

scholarly journals The Influence of the Thickness of Compact TiO2 Electron Transport Layer on the Performance of Planar CH3NH3PbI3 Perovskite Solar Cells

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3295
Author(s):  
Andrzej Sławek ◽  
Zbigniew Starowicz ◽  
Marek Lipiński
Keyword(s):  
Solar Cells ◽  
Electron Transport ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Perovskite Solar Cells ◽  
Precursor Solution ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Transport Layer ◽  
Electron Transport Layer

In recent years, lead halide perovskites have attracted considerable attention from the scientific community due to their exceptional properties and fast-growing enhancement for solar energy harvesting efficiency. One of the fundamental aspects of the architecture of perovskite-based solar cells (PSCs) is the electron transport layer (ETL), which also acts as a barrier for holes. In this work, the influence of compact TiO2 ETL on the performance of planar heterojunction solar cells based on CH3NH3PbI3 perovskite was investigated. ETLs were deposited on fluorine-doped tin oxide (FTO) substrates from a titanium diisopropoxide bis(acetylacetonate) precursor solution using the spin-coating method with changing precursor concentration and centrifugation speed. It was found that the thickness and continuity of ETLs, investigated between 0 and 124 nm, strongly affect the photovoltaic performance of PSCs, in particular short-circuit current density (JSC). Optical and topographic properties of the compact TiO2 layers were investigated as well.

Electron-transport-layer-free two-dimensional perovskite solar cells based on a flexible poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) cathode

2021 ◽  
Author(s):  
Zhihai Liu ◽  
Lei Wang ◽  
Chongyang Xu ◽  
Xiaoyin Xie
Keyword(s):  
Solar Cells ◽  
Electron Transport ◽  
Power Conversion ◽  
Perovskite Solar Cells ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Two Dimensional ◽  
High Power Conversion Efficiency ◽  
Long Term Stability

Recently, Ruddlesden–Popper two-dimensional (2D) perovskite solar cells (PSCs) have been intensively studied, owing to their high power conversion efficiency (PCE) and excellent long-term stability. In this work, we fabricated electron-transport-layer-free...

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