Next Issue

Table of Contents

Computation, Volume 1, Issue 1 (June 2013), Pages 1-26

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
View options order results:
result details:
Displaying articles 1-2
Export citation of selected articles as:

Research

Open AccessArticle Effect of Isotopic Substitution on Elementary Processes in Dye-Sensitized Solar Cells: Deuterated Amino-Phenyl Acid Dyes on TiO2
Computation 2013, 1(1), 1-15; doi:10.3390/computation1010001
Received: 23 January 2013 / Revised: 4 February 2013 / Accepted: 1 March 2013 / Published: 11 March 2013
Cited by 3 | PDF Full-text (1072 KB) | HTML Full-text | XML Full-text
Abstract
We present the first computational study of the effects of isotopic substitution on the operation of dye-sensitized solar cells. Ab initio molecular dynamics is used to study the effect of deuteration on light absorption, dye adsorption dynamics, the averaged over vibrations driving force
[...] Read more.
We present the first computational study of the effects of isotopic substitution on the operation of dye-sensitized solar cells. Ab initio molecular dynamics is used to study the effect of deuteration on light absorption, dye adsorption dynamics, the averaged over vibrations driving force to injection (∆Gi) and regeneration (∆Gr), as well as on promotion of electron back-donation in dyes NK1 (2E,4E-2-cyano-5-(4-dimethylaminophenyl)penta-2,4-dienoic acid) and NK7 (2E,4E-2-cyano-5-(4-diphenylaminophenyl)penta-2,4-dienoic acid) adsorbed in monodentate molecular and bidentate bridging dissociative configurations on the anatase (101) surface of TiO2. Deuteration causes a red shift of the absorption spectrum of the dye/TiO2 complex by about 5% (dozens of nm), which can noticeably affect the overlap with the solar spectrum in real cells. The dynamics effect on the driving force to injection and recombination (the difference between the averaged <∆Gi,r> and ∆Gi,requil at the equilibrium configuration) is strong, yet there is surprisingly little isotopic effect: the average driving force to injection <∆Gi> and to regeneration <∆Gr> changes by only about 10 meV upon deuteration. The nuclear dynamics enhance recombination to the dye ground state due to the approach of the electron-donating group to TiO2, yet this effect is similar for deuterated and non-deuterated dyes. We conclude that the nuclear dynamics of the C-H(D) bonds, mostly affected by deuteration, might not be important for the operation of photoelectrochemical cells based on organic dyes. As the expectation value of the ground state energy is higher than its optimum geometry value (by up to 0.1 eV in the present case), nuclear motions will affect dye regeneration by recently proposed redox shuttle-dye combinations operating at low driving forces. Full article
(This article belongs to the Special Issue Feature Papers)
Open AccessArticle Structural Features That Stabilize ZnO Clusters: An Electronic Structure Approach
Computation 2013, 1(1), 16-26; doi:10.3390/computation1010016
Received: 8 April 2013 / Revised: 16 May 2013 / Accepted: 23 May 2013 / Published: 31 May 2013
Cited by 3 | PDF Full-text (1884 KB) | HTML Full-text | XML Full-text
Abstract
We show that a simple approach to building small computationally inexpensive clusters offers insights on specific structural motifs that stabilize the electronic structure of ZnO. All-electron calculations on ZniOi needle (i = 6, 9, 12, 15, and 18) and plate
[...] Read more.
We show that a simple approach to building small computationally inexpensive clusters offers insights on specific structural motifs that stabilize the electronic structure of ZnO. All-electron calculations on ZniOi needle (i = 6, 9, 12, 15, and 18) and plate (i = 9 and 18) clusters within the density functional theory (DFT) formalism show a higher stability for ZnO needles that increases with length. Puckering of the rings to achieve a more wurtzite-like structure destabilizes the needles, although this destabilization is reduced by going to infinite needles (calculated using periodic boundary conditions). Calculations of density of states (DOS) curves and band gaps for finite clusters and infinite needles highlight opportunities for band-gap tuning through kinetic control of nanocrystal growth. Full article
(This article belongs to the Section Computational Chemistry)
Figures

Journal Contact

MDPI AG
Computation Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
computation@mdpi.com
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Computation
Back to Top