scholarly journals Structure and Energetics of Dye-Sensitized NiO Interfaces in Water from Ab Initio MD and Large-Scale GW Calculations

Author(s):  
Alekos Segalina ◽  
Sébastien Lebègue ◽  
Dario Rocca ◽  
Simone Piccinin ◽  
Mariachiara Pastore
2014 ◽  
Vol 16 (30) ◽  
pp. 16246-16254 ◽  
Author(s):  
Kristian B. Ørnsø ◽  
Christian S. Pedersen ◽  
Juan M. Garcia-Lastra ◽  
Kristian S. Thygesen

We present a systematic study of the level alignment of 5145 porphyrin based dyes for dye sensitized solar cells.


2019 ◽  
Author(s):  
Liqun Cao ◽  
Jinzhe Zeng ◽  
Mingyuan Xu ◽  
Chih-Hao Chin ◽  
Tong Zhu ◽  
...  

Combustion is a kind of important reaction that affects people's daily lives and the development of aerospace. Exploring the reaction mechanism contributes to the understanding of combustion and the more efficient use of fuels. Ab initio quantum mechanical (QM) calculation is precise but limited by its computational time for large-scale systems. In order to carry out reactive molecular dynamics (MD) simulation for combustion accurately and quickly, we develop the MFCC-combustion method in this study, which calculates the interaction between atoms using QM method at the level of MN15/6-31G(d). Each molecule in systems is treated as a fragment, and when the distance between any two atoms in different molecules is greater than 3.5 Å, a new fragment involved two molecules is produced in order to consider the two-body interaction. The deviations of MFCC-combustion from full system calculations are within a few kcal/mol, and the result clearly shows that the calculated energies of the different systems using MFCC-combustion are close to converging after the distance thresholds are larger than 3.5 Å for the two-body QM interactions. The methane combustion was studied with the MFCC-combustion method to explore the combustion mechanism of the methane-oxygen system.


2020 ◽  
Vol 18 (1) ◽  
pp. 287-294
Author(s):  
Harsasi Setyawati ◽  
Handoko Darmokoesoemo ◽  
Irmina Kris Murwani ◽  
Ahmadi Jaya Permana ◽  
Faidur Rochman

AbstractThe demands of ecofriendly technologies to produce a reliable supply of renewable energy on a large scale remains a challenge. A solar cell based on DSSC (Dye-Sensitized Solar Cell) technology is environmentally friendly and holds the promise of a high efficiency in converting sunlight into electricity. This manuscript describes the development of a light harvester system as a main part of a DSSC. Congo red dye has been functionalized with metals (Fe, Co, Ni), forming a series of complexes that serve as a novel light harvester on the solar cell. Metal-congo red complexes have been characterized by UV-VIS and FTIR spectroscopy, and elemental analyses. The performance of metal complexes in capturing photons from sunlight has been investigated in a solar cell device. The incorporation of metals to congo red successfully improved of the congo red efficiency as follows: Fe(II)-congo red, Co(II)-congo red and Ni(II)-congo red had efficiencies of 8.17%, 6.13% and 2.65%, respectively. This research also discusses the effect of metal ions on the ability of congo red to capture energy from sunlight.


2012 ◽  
Vol 403 ◽  
pp. 012019 ◽  
Author(s):  
Pieter Maris ◽  
H Metin Aktulga ◽  
Mark A Caprio ◽  
Ümit V Çatalyürek ◽  
Esmond G Ng ◽  
...  

2002 ◽  
Vol 731 ◽  
Author(s):  
R.A. Evarestov ◽  
R.I. Eglitis ◽  
S. Piskunov ◽  
E. A. Kotomin ◽  
G. Borstel

AbstractUsing the Unrestricted Hartree-Fock method and supercells containing up to 160 atoms, we calculated the energy level positions in the gap and atomic geometry for the Fe4+ impurity substituting for a host Ti atom in SrTiO3. In agreement with experiment, the high spin (S=2) state is much lower in energy than the zero-spin state. The energy level positions strongly depend on the asymmetric displacement mode of the six nearest O ions which is a combination of the Jahn-Teller and breathing modes. A considerable covalent bonding between the Fe ion and four nearest O ions takes place.


2012 ◽  
Vol 53 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Mai Anh Tuan ◽  
Nguyen Ngoc Ha ◽  
Vu Quoc Trung ◽  
Luong T. Thu Thuy ◽  
Dang Xuan Thu

2021 ◽  
Author(s):  
T Sumathi ◽  
Sonia A Fredricka ◽  
G Deepa

Abstract In the last two decades, dye sensitized solar cells (DSSCs) have gotten a lot of attention from researchers and have progressed quickly. To promote commercialization and large-scale application of DSSCs, their efficiency should be increased. This paper details significant advancements in advanced NiMoS3/BC nanocomposites for improving photoanodes and DSSC conversion efficiencies. The fabricated electrode samples were characterized by XRD, SEM, TEM, Raman, UV, PL and BET to explore the structural, morphological and optical properties. A significant reduction band gap with enhanced light absorption and rapid prevention of electron hole pair was explored by UV-DRS and PL studies. The photocurrent density-voltage (J-V) and IPCE characteristics were analyzed for assembled solar cell. The NiMoS3/BC (NMSC5) nanocomposite DSSC showed a PCE of 8.85%, far higher than that of the NiMoS3 (2.45%) and a PCE value equivalent to Pt CE (4.79 %). The enhanced PCE of the proposed electrodes are also discussed in scientifically.


1995 ◽  
Vol 408 ◽  
Author(s):  
D. J. Sullivan ◽  
E. L. Briggs ◽  
C. J. Brabec ◽  
J. Bernholc

AbstractWe have developed a set of techniques for performing large scale ab initio calculations using multigrid accelerations and a real-space grid as a basis. The multigrid methods permit efficient calculations on ill-conditioned systems with long length scales or high energy cutoffs. We discuss the design of pseudopotentials for real-space grids, and the computation of ionic forces. The technique has been applied to several systems, including an isolated C60 molecule, the wurtzite phase of GaN, a 64-atom cell of GaN with the Ga d-states in valence, and a 443-atom protein. The method has been implemented on both vector and parallel architectures. We also discuss ongoing work on O(N) implementations and solvated biomolecules.


2014 ◽  
Vol 16 (32) ◽  
pp. 17196-17205 ◽  
Author(s):  
Siv G. Aalbergsjø ◽  
Ewald Pauwels ◽  
Andy Van Yperen-De Deyne ◽  
Veronique Van Speybroeck ◽  
Einar Sagstuen

Stabilization of radical products is connected to charge transfer along hydrogen bonds.


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