Acta Chim. Sinica ›› 2015, Vol. 73 ›› Issue (11): 1214-1218.DOI: 10.6023/A15060430 Previous Articles    



周沃华a, 陈蓉a, 吴子文a, 丁丹丹a, 徐志广a,b, 许旋a,b,c,d, 罗一帆a,b   

  1. a 华南师范大学化学与环境学院 广州 510006;
    b 教育部环境理论化学重点实验室 广州 510006;
    c 广东省高校电化学储能与发电技术重点实验室 广州 510006;
    d 华南师范大学电化学储能材料与技术教育部工程研究中心 广州 510006
  • 投稿日期:2015-06-24 发布日期:2015-11-19
  • 通讯作者: 许旋
  • 基金资助:

    项目受广东省自然科学资金项目(No. S2012010008763), 广东省教育部产学研项目(No. 2010B090400184)和广州市科技攻关项目(No. 2011J4300063)资助.

Electronic Transport Properties of Asymmetric Metal String Complex [Cu2Pt(npa)4X2](X=Cl-, NCS-)

Zhou Wohuaa, Chen Ronga, Wu Ziwena, Ding Dandana, Xu Zhiguanga,b, Xu Xuana,b,c,d, Luo Yifana,b   

  1. a School of Chemistry & Environment, South China Normal University, Guangzhou 510006;
    b Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, Guangzhou 510006;
    c Key Laboratory of Electrochemical Technology on Energy Storage and Power Generation in Guangdong Universities, Guangzhou 510006;
    d Engineering Research Center of Materials and Technology for Electrochemical Energy Storage, Ministry of Education of China, South China Normal University, Guangzhou 510006
  • Received:2015-06-24 Published:2015-11-19
  • Supported by:

    Project supported by the Natural Science Foundation of Guangdong Province (No. S2012010008763), Ministry of Education and Guangdong Province (No. 2010B090400184), Science and Technology Program of Guangzhou City (No. 2011J4300063).

The asymmetric heterometal string complexes [Cu2Pt(npa)4X2] (X=Cl-(1), NCS-(2), npa=2-naphthyridyl- phenylamine) are suitable candidates for promising inorganic molecule rectifiers. The electronic structures and transmission properties of them were investigated by theoretical calculation using Density Function Theory BP86 and Non Equilibrium Green's Functions method. The results revealed that: (1) Since the interaction between axial ligand NCS- and Cu atom is stronger than that of Cl-Cu, the Cu-Cu bond of complex 1 is stronger than that in 2, while its Cu-Pt bond is weaker than that in 2. Therefore, complex 1 has smaller energy gap ΔE between π*Pt dxz/yz and π*Cu-Cu orbital compared with that of 2. (2) The transmission channels of 1 and 2 both are β spin π* orbitals, which are mainly combination of π*Cu-Cu and π*Pt dxz/yz orbital. The smaller ΔE, the larger delocalization of π* channel, and hence the stronger transmission capacity. When the positive bias is less than 0.15 V and under negative bias, current of 1 is greater than that of 2 for the smaller ΔE of 1. However when the positive bias is larger than 0.15 V, current of 2 is significantly higher than that of 1 for the stronger delocalization of π* channel in 2. (3) The complex 2 has better rectifying effect. With a larger ΔE, the transmission of Pt → Cu direction is easier and the rectifying effect is stronger. Current of 2 under the positive bias is significantly greater than that in negative bias. When the bias is larger than 0.15 V, the rectified ratio of 2 is 10~40 times larger than 1. (4) With the ΔEβ smaller than ΔEα, the transmission capacity of α spin channel is less than β, and the effect of the spin filter will be stronger for the larger difference between ΔEβ and ΔEα. Both 1 and 2 have significant spin filter effect (up to 80%~99%).

Key words: metal string complex, density function theory, non equilibrium green's functions, electronic transport, molecule rectifier