Lithium Adatoms And Clusters On PPV: An Ab Initio Investigation

Conductive polymer as the organic conjugated polymer has a wealth ofelectrical,optical and magnetic properties,which is widely used in nonlinear opticalmaterials, field-effect transistor (FET), light-emitting diode (LED) and photovoltaiccells and other aspects. Poly(p-phenylene vinylene) belongs to a conductivepolymer.ue to excellent optoelectronic properties, is one of the most studied and mostpromising photovoltaic materials.But pure PPV material has certain defects in theoptical and electrical properties,so appear a lot of PPV modified materials in recentyears. This article is mainly from the perspective of a modified PPV materials usingfirst-principles density functional theory calculations to study the lithium clustersadsorbed on PPV the nature of optical and electrical.At the same time, comparing thedifference nature of have the same atomic number of different cluster structureadsorbed on PPV chain.(1) By optimizing lithium clusters (Lin,n=1~10) structure,obtained lithiumclusters the most stable configuration, and that with atomic number increasing theaverage binding energy is a growing trend, the number of atoms is2,4,7clusterstructure performance characteristics of magic numbers.(2) By optimizing lithium cluster(Lin,n=1~10) absorbed on PPV found that withatomic number increasing the average binding energy have a certain fluctuation,andwhen Li5clusters adsorbed on PPV chain corresponding to the binding energy islargest; Simultaneously,we get that atoms number is2,4,6,8clusters structureadsorbed on PPV chain is relatively stable.(3) Optimized a lithium atom,two and three lithium atoms different structureadsorption in different locations of PPV chain and comparing their density of state.As can be seen from the obtained results after PPV chain adsorption metal lithiumatoms that their overall performance the nature of the conductor.(4) We calculated optical absorption coefficients of a lithium atom,two and threelithium atoms different structure adsorbed in different locations of PPV chain and found that the2Li/PPV-1structure corresponding the solar spectrum than a singlePPV chain has a greatly improved.The light absorption coefficient of3Li/PPV havesome enhancements compare a single PPV chain.(5) We calculated and compare the reflection spectrum and the the real andimaginary parts of conductivity corresponding structure of separately PPV chain, PPVchain adsorbed the different structure of one to three lithium atoms.We obtainedresults verify the conclution that the whole system show metalicity after PPV chainadsorbed lithium atoms.(6) We observed that different structure of two lithium atoms adsorb on PPVchain that the magic number structure adsorption is less stable than the no-magicnumber structure adsorption.2Li/PPV-1structure show more strong light absorptionand conductivity.