Abstract
We present a computational density functional theory study of the potential to improve the solar absorbance of small organic dyes featuring a phenothiazine donor and an acceptor moiety that combines a thiophene unit and a cyanoacrylic group. We consider different conjugation orders and functional groups on and around the thiophene unit, including electron-donating and electron-withdrawing moieties (H, F, CH3, CF3, and CN). We predict that by combining change of conjugation order and functionalization with electron withdrawing CN groups, it must be possible to decrease the excitation energy by up to 60 % vs. the parent dye (which would correspond to a redshift of the absorption peak maximum from 450 nm to 726 nm), effectively enabling red light absorption with small dyes. The contraction of the band gap is mostly due to the stabilization of the LUMO (by up to 1.8 eV), so that-in spite of the kinetic redundancy of the parent dye with respect to the conduction-band minimum of TiO2-care must be taken to ensure efficient injection when using the dyes in dye-sensitized solar cells. By studying 50 dyes, of which 44 are new dyes that are studied for the first time in this work, we identify parameters (such as charges, dihedral angles b...Continue Reading
References
Feb 1, 1996·Journal of Molecular Graphics·W HumphreyK Schulten
May 1, 2004·Annual Review of Physical Chemistry·M A L Marques, E K U Gross
Aug 12, 2005·Chemical Reviews·Jacopo TomasiRoberto Cammi
Mar 24, 2007·Chemical Reviews·Veaceslav CoropceanuJean-Luc Brédas
Sep 14, 2007·Chemical Communications : Chem Comm·Haining TianLicheng Sun
Apr 2, 2009·Journal of the American Chemical Society·Sara E KoopsJames R Durrant
Feb 16, 2010·International Journal of Cardiology·P EwertF Uhlemann
Sep 14, 2010·Chemical Reviews·Anders HagfeldtHenrik Pettersson
Apr 26, 2011·The Journal of Chemical Physics·A KarolewskiS Kümmel
Jan 25, 2013·Physical Chemistry Chemical Physics : PCCP·Makoto KomatsuHiroshi Segawa
Dec 7, 2013·Advanced Materials·Alan J Heeger
Feb 8, 2011·Journal of Chemical Theory and Computation·Denis Jacquemin, Carlo Adamo
May 10, 2011·Journal of Chemical Theory and Computation·Ryan M Richard, John M Herbert
Sep 8, 2009·Journal of Chemical Theory and Computation·Denis JacqueminCarlo Adamo