The Relationship Between The Structure And Properties Of Multi-anchoring Dye

With the global energy crisis and fossil energy(such as coal and oil)resources reduction,this prompted researchers to search of renewable and non-polluting energy.Therefore,solar energy has become an alternate energy resource and has attracted wide attention from researchers.Among the many solar cells,the Dye sensitized solar cell(DSSC)as the third generation solar cell is a promising class of optoelectronic devices because of its low cost,simple manufacture and friendly environment.The sensitizer is the core of the DSSCs,and plays the role of absorbing photons and injecting electrons into the conduction band of the semiconductor,so its performance directly affects the PCE.To date,the overall power conversion efficiency(PCE)of DSSCs have reached 13%based on ruthenium complex dyes.Although this type of devices have shown the superior efficiency,the large-scale fabrication has been limited due to the major drawback of ruthenium complex dyes,such as scarce precious metals.Hence,it is important for the study of metal free DSSCs.This paper mainly includes two parts of work;in the first part,the photoelectric properties of organic solar cell dye molecules were analyzed by using DFT and TD-DFT methods.The results showed that with the increasing of molecular structure,LUMO energy levels and energy gaps decrease.TPA(DPP-P)2 displays the maximum red-shift and higher open-circuit voltage.Ionization potentials decrease and electron affinities increase with the increase of molecular structure.The hole and electron recombination energies of TPA(DPP-P)2 is the smallest,so TPA(DPP-P)2 has a better hole transport capability.Four molecules are designed on the basis of the original molecules,named after TPA-DPP-1,TPA-DPP-2,TPA(DPPP)2-1,TPA(DPP-P)2-2.The data shows that two-CNs were introduced into the molecules,energy gaps decrease and absorption peak makes red-shift.The introduction of a-CN is favorable to improve the electron injection free energies and dye regeneration free energies.The introduction of a side chain makes LHE increase;however,make absorption peak blue-shift.The performance of the dye can be controlled by the introduction of the functional group and provides valuable information for the experiment.In the second part,a series of A-D-?-D-A double-anchoring organic dyes(MA-201-MA-206)with different core spacers were designed.The short-circuit current density and open-circuit voltage can be directly estimated from simulated micro-parameters.The results reveal that dyes MA-201-MA-206 have narrower energy gap and higher molar extinction coefficient compared with the referenced dye(MA-2),and designed molecules(MA-201-MA-206)also exhibit the higher light-harvesting efficiency,electron accepting power driving force of electron injection and lower chemical hardness.Those parameters suggested that the designed molecules should have the higher short-circuit current density and dyes MA-201-MA-206 have higher dipole moment,which will increase the open-circuit voltage.Furthermore,one anchoring model and two anchoring models were compared from the energy level and spectra.It is expected that the dyes(MA-201-MA-206)will be potential,comparative investigation can provide a train of thought to design and screen out high performance dyes candidates,and driving force.