02096nas a2200193   4500008004100000022001400041245013300055210006900188260007100257300001600328490000800344520132200352100002401674700002001698700001401718700001701732700002301749856013001772       2014                        eng d  a1932-744700aDesign of efficient metal-free organic dyes having an azacyclazine scaffold as the donor fragment for dye-sensitized solar cells0 aDesign of efficient metalfree organic dyes having an azacyclazin  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a20763-207710 v1183 a<p>The energy conversion efficiency of dye-sensitized solar cells derived from organic dye molecules has seen immense interest recently. In this work, we report a series of organic donor molecules with enhanced energy conversion efficiency using ?-spacers and cyanoacrylic acid as an anchoring group (2-6). Density functional theory (DFT) and time-dependent DFT calculations of these molecules have been performed to examine their electronic structures and absorption spectra before and after binding to the semiconductor titanium dioxide surface. The computational results suggest that dyes 4 and 6 have a larger driving force (Delta G(inject) = -1.66 and -1.80 eV, respectively) and light-harvesting efficiency (LHE = 0.99) in the series of donor molecules studied. Thus, these dyes should possess a larger short-circuit photocurrent density (J(sc)) compared to the other examined dyes. The reported Delta G(inject) (-1.62 eV) and LHE (0.98) for compound 1, calculated with the same level of theory, were lower than those of the designed 4 and 6 dyes. Furthermore, the DFT calculations showed that the open-circuit photovoltage (V-oc) is improved with the vertical dipole moment and number of photoinjected electrons for 4 and 6. Dyes 4 and 6 are expected to exhibit high solar-energy-to-electricity conversion.</p>1 aBiswas, Abul, Kalam1 aBarik, Sunirmal1 aSen, Anik1 aDas, Amitava1 aGanguly, Bishwajit  uhttps://library.ncl.res.in/content/design-efficient-metal-free-organic-dyes-having-azacyclazine-scaffold-donor-fragment-dye-0