TY  - JOUR
A1  - Marom, Noa
A1  - Körzdörfer, Thomas
A1  - Ren, Xinguo
A1  - Tkatchenko, Alexandre
A1  - Chelikowsky, James R.
T1  - Size effects in the interface level alignment of dye-Sensitized TiO2 clusters
JF  - The journal of physical chemistry letters
N2  - The efficiency of dye-sensitized solar cells (DSCs) depends critically on the electronic structure of the interfaces in the active region. We employ recently developed dispersion-inclusive density functional theory (DFT) and GW methods to study the electronic structure of TiO2 clusters sensitized with catechol molecules. We show that the energy level alignment at the dye-TiO2 interface is the result of an intricate interplay of quantum size effects and dynamic screening effects and that it may be manipulated by nanostructuring and functionalizing the TiO2. We demonstrate that the energy difference between the catechol LUMO and the TiO2 LUMO, which is associated with the injection loss in DSCs, may be reduced significantly by reducing the dimensions of nanostructured TiO2 and by functionalizing the TiO2 with wide-gap moieties, which contribute additional screening but do not interact strongly with the frontier orbitals of the TiO2 and the dye. Precise control of the electronic structure may be achieved via "interface engineering" in functional nanostructures.
Y1  - 2014
U6  - https://doi.org/10.1021/jz5008356
SN  - 1948-7185
VL  - 5
IS  - 14
SP  - 2395
EP  - 2401
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Knight, Joseph W.
A1  - Wang, Xiaopeng
A1  - Gallandi, Lukas
A1  - Dolgounitcheva, Olga
A1  - Ren, Xinguo
A1  - Ortiz, J. Vincent
A1  - Rinke, Patrick
A1  - Körzdörfer, Thomas
A1  - Marom, Noa
T1  - Accurate Ionization Potentials and Electron Affinities of Acceptor Molecules III: A Benchmark of GW Methods
JF  - Journal of chemical theory and computation
N2  - The performance of different GW methods is assessed for a set of 24 organic acceptors. Errors are evaluated with respect to coupled cluster singles, doubles, and perturbative triples [CCSD(T)] reference data for the vertical ionization potentials (IPs) and electron affinities (EAs), extrapolated to the complete basis set limit. Additional comparisons are made to experimental data, where available. We consider fully self-consistent GW (scGW), partial self-consistency in the Green’s function (scGW0), non-self-consistent G0W0 based on several mean-field starting points, and a “beyond GW” second-order screened exchange (SOSEX) correction to G0W0. We also describe the implementation of the self-consistent Coulomb hole with screened exchange method (COHSEX), which serves as one of the mean-field starting points. The best performers overall are G0W0+SOSEX and G0W0 based on an IP-tuned long-range corrected hybrid functional with the former being more accurate for EAs and the latter for IPs. Both provide a balanced treatment of localized vs delocalized states and valence spectra in good agreement with photoemission spectroscopy (PES) experiments.
Y1  - 2016
U6  - https://doi.org/10.1021/acs.jctc.5b00871
SN  - 1549-9618
SN  - 1549-9626
VL  - 12
SP  - 615
EP  - 626
PB  - American Chemical Society
CY  - Washington
ER  -