First Principles Modeling of Eosin-Loaded ZnO Films: A Step toward the Understanding of Dye-Sensitized Solar Cell Performances
- 17 September 2009
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 131 (40), 14290-14298
- https://doi.org/10.1021/ja902833s
Abstract
A theoretical investigation of eosin-Y (EY) loaded ZnO thin films, the basic components of a dye-sensitized solar cell (DSSC), is presented. The EY/ZnO wurtzite (10-10) system has been fully described within a periodic approach using density functional theory (DFT) and a hybrid exchange-correlation functional. Reduced systems were also analyzed to simulate an electron transfer from the dye to the substrate. Injection times from dye to the semiconductor were calculated using the Newns-Anderson approach. Finally, the UV-visible spectra of EY/ZnO films were simulated using a time-dependent DFT approach and compared to that of the EY molecule computed in solution. The results obtained highlight that EY strongly adsorbs on the ZnO substrate contributing significantly to the electronic structure of the adsorbed system. The UV-visible spectral signature of the isolated EY molecule is still found when adsorbed on ZnO but the analysis of Gamma-point crystalline orbitals reveals that a direct HOMO -> LUMO excitation cannot lead to a direct electron injection into the semiconductor, the first unoccupied orbital with contributions from the ZnO substrate being the LUMO + 1. As a consequence, a two photon injection mechanism is proposed explaining the low efficiency of the EY/ZnO solar cells. On this basis, possible strategies for enhancing the cell efficiency are presented and discussed.Keywords
This publication has 86 references indexed in Scilit:
- Spectral properties of self-assembled squaraine–tetralactam: a theoretical assessmentPhysical Chemistry Chemical Physics, 2009
- Theoretical Insights on the Electronic Properties of Eosin Y, an Organic Dye for Photovoltaic ApplicationsThe Journal of Physical Chemistry A, 2008
- Theoretical Analysis of the Electronic Properties of N3 DerivativesThe Journal of Physical Chemistry A, 2007
- Density functional theory study of MnO by a hybrid functional approachPhysical Review B, 2005
- Calculated Structural and Electronic Interactions of the Ruthenium Dye N3 with a Titanium Dioxide NanocrystalThe Journal of Physical Chemistry B, 2005
- Dissociation, tautomerism and electroreduction of xanthene and sulfonephthalein dyes inN,N‐dimethylformamide and other solventsJournal of Physical Organic Chemistry, 2003
- Cathodic Electrodeposition of ZnO/Eosin Y Hybrid Thin Films from Oxygen-Saturated Aqueous Solution of ZnCl[sub 2] and Eosin YJournal of the Electrochemical Society, 2003
- A Theoretical Investigation of the Ground and Excited States of Selected Ru and Os Polypyridyl Molecular DyesThe Journal of Physical Chemistry A, 2002
- Steady hydrogen evolution from water on Eosin Y-fixed TiO2 photocatalyst using a silane-coupling reagent under visible light irradiationJournal of Photochemistry and Photobiology A: Chemistry, 2000
- Triplet–triplet absorption of some organic molecules determined by picosecond laser excitation and time-delayed picosecond light continuum probingJournal of Photochemistry and Photobiology A: Chemistry, 1999