Theoretical Research On Transport Properties Of （Si_nC₄）_k

Polysilane is a kind of high polymer which is composed by Si-Si bonds andit is σ conjugated structure. It includs linear polysilane and cyclosilane. Siliconatom has the3d vacant orbital, which makes the electron transfer easily. Thismakes that it has an unique conductive property. Polyacetylene is a linearpolymer that has π-conjugate structure. It could form n-type and p-typesemiconductors after chemical or electrochemical doping, and the electricalconductivities cold catch up with metal. Studying on the combination of cyclicpolysilane and polyacetylene by experimental and theoretical research cancombine and configure structures at all levels on purpose. It could make greatcontribution to exploiting new conducting polymer materials.Firstly, this paper makes use of the Gaussian03package under6-31+G*tooptimizate the geometric structure of copolymer （Si_nC₄）_kk=1⁴; n=3⁶with thecyclic polysilanes and polyacetylene. It combines non-Green balance functionand density functional theory uses ATK package to caclculate electron transportproperty of the experimental system by theory. Thus it can get current-voltagecurve. After analysis of the calculation results and find that: in （Si_nC₄）_k, when nincreases, the conductive property of the experimental system gradually drops. In（Si_nC₄）_k, when k increases, the conductive property of the experimental systemgradually drops. Thus the cyclic polysilane of smaller molecule can be used asexcellent semiconductor materials. For （Si_nC₄）_k, it can be found a negativedifferential resistance effect （NDR） and it could be illustrated from thetransmission spectrums, density of states （DOS） and MPSH state.