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使用密度泛函理论(BP86)结合非平衡态格林函数(NEGF)方法研究金属串配合物[Cu2Pt(npa)4X2](X=Cl-(1),NCS-(2);npa=2-naphthyridylphenylamine)的电子结构和电子传输性质,研究发现:(1)由于轴向配体NCS-与Cu的结合比Cl-的强,使配合物1的Cu—Cu键比2的强而Cu—Pt键比2的弱,故1的π*Pt dxz/yz轨道与π*Cu-Cu能级差ΔE比2小.(2)1和2的传输通道均是β自旋的π*轨道,主要由π*Cu-Cu和π*Pt dxz/yz轨道组合而成.ΔE越小π*越离域,传输能力越强.在负偏压下和正偏压小于0.15 V时,1的电流大于2;但正偏压大于0.15 V后2的β电流显著高于1.(3)2具有较好的整流效应.ΔE越大,Pt→Cu方向的传输越容易,整流效应越强.正偏压下2的电流显著大于负偏压下的电流,0.15 V后2的整流比比1高10~40倍.(4)因ΔEβ<ΔEα,α自旋通道传输能力小于β自旋的,1和2具有良好的自旋过滤效应(高达80%~99%).
The density functional theory (BP86) combined with the non-equilibrium Green’s function (NEGF) method was used to study the metal complex [Cu2Pt (npa) 4X2] ) Electronic structure and electron transport properties, the study found that: (1) due to the axial ligand NCS- and Cu than Cl- strong, so that the complex 1 Cu-Cu bond stronger than 2 and Cu-Pt bond (1) The π * Pt dxz / yz orbitals and the π * Cu-Cu energy level difference ΔE are smaller than 2. (2) The transport channels 1 and 2 are all π * orbitals of β-spin and are mainly composed of π * The combination of Cu-Cu and π * Pt dxz / yz orbitals. The smaller the ΔE, the greater the delocalization of π * and the stronger the transport. The current of 1 is greater than 2 at negative bias and at positive bias less than 0.15 V; When the positive bias is greater than 0.15 V, the β current of 2 is significantly higher than 1. (3) 2 has a good rectification effect. The larger the ΔE, the easier the transfer in the Pt → Cu direction and the stronger the rectification. Of the current is significantly greater than the negative bias current, 0.15 V after the rectification ratio of 2 to 10 to 40 times higher than 1. (4) ΔEβ <ΔEα, α spin channel transmission capacity is less than β spin, 1 and 2 have good The spin filter effect (up to 80% ~ 99%).