Rational Design Of Highly Efficient Organic Dyes And The Analysis Of Key Parameters Of Energy Conversion Efficiency For Dye-sensitized Solar Cells

Based on the highly efficient experiment dyes which have the structure of donor-?conjugated bridge-acceptor?D-?-A?and donor-acceptor?D-A?,we designed a series of novel organic dyes.For screening promising dye molecules,we further calculate their energy absorption spectra,driving force of injection(?35?G_inj)and regeneration(?35?G_reg)and the frontier molecular orbital distribution by using the density functional theory?DFT?and time-dependent DFT?TDDFT?.The screened dyes which adsorbed to anatase TiO₂ substrate will benefit to investigate the mechanism of implantation/reduction and the lifetime of the dyes,finally we can analyze the influences of different organic dyes on the efficiency of DSSCs.The main works in this paper are as follows:1.For screening high efficiency?conjugated bridge and D-?-A structure organic dyes,we substitute different electron?-conjugated bridges and acceptor units of C217,then obtained SPL101-SPL108 dyes.By comparing the dye molecular structure,UV-Vis absorption,driving force of injection and regeneration and the electronic cloud distribution,we finally obtained promising?conjugated bridge and the high efficiency D-?-A structure organic dyes SPL106 and SPL108.2.For screening high efficiency D-A structure organic dyes,we obtained a series of dyes ME01-ME06 by modifying the electron acceptor units of C281.We also investigated the molecular orbitals,absorption spectra,light harvesting efficiency and the effect of different heteroatom on the properties of organic dyes,finally screened ME01,ME02 and ME04 as candidates which will further adsorbed to anatase TiO₂substrate.3.The experimental dyes C281,ME01,ME02 and ME04 was used as the photosensitizer,which were adsorbed on the surface of TiO₂.We finally found the sensitizers bind to the TiO₂ substrate via bidentate bridging mode is the most stable binding.By calculating the light harvesting efficiency,driving force of injection and regeneration,the number of injected electrons and excited state lifetime,which mainly affect the efficiency of DSSCs,our calculations revealed ME02 and ME04 might be promising candidates for red to infrared light absorption,shorter injection time,more injected electrons and larger photovoltage which may offer improved sunlight-to-electricity conversion efficiency when absorbed with TiO₂ slab.