Thermally activated electrical conductivity of thin films of bis (phthalocyaninato)terbium(III) double decker complex

THIN SOLID FILMS

卷:646

Article

Murdey, Richard¹  Katoh, Keiichi²  Yamashita, Masahiro^2,3  Sato, Naoki^1,4 

[1] Kyoto Univ, Inst Chem Res, Uji, Kyoto 6110011, Japan

[2] Tohoku Univ, Grad Sch Sci, Dept Chem, Aoba Ku, Sendai, Miyagi 9808578, Japan

[3] Tohoku Univ, Adv Inst Mat Res, WPI Res Ctr, Aoba Ku, Sendai, Miyagi 9808578, Japan

[4] Nankai Univ, Sch Mat & Engn, Tianjin 300350, Peoples R China

关键词: Electrical conduction;    Molecular electronics;    Phthalocyanine;    Thin films;    Organic radicals;    Organic semiconductors;   

DOI  :  10.1016/j.tsf.2017.11.024

来源: Elsevier

【 摘 要 】

The temperature and field dependence of the electrical conductance of neutral radical bis(phthalocyaninato) terbium(III) (TbPc2) thin films was measured in situ under ultrahigh vacuum. The films behave electrically as narrow gap intrinsic semiconductors, having high conductivity and weakly thermally activated conductance. Taking advantage of the exceptionally high electrical stability of the material and the fast-settling response in the low-field region, precise measurements of the temperature dependence could resolve a linear temperature dependence in the pre-exponential factor of the conduction equation. The activation energy of conductance of the annealed TbPc2 film was determined to be 0.158 eV after adjusting the fitting procedure to take into account the temperature dependent pre-exponential. This new conductance equation, which differs only slightly from the usual Arrhenius expression, arises as the natural consequence of thermal excitation of carriers from a continuous density of deep trap states, or a similar activated process where either the states or the barrier heights distribute over a finite width.

【 授权许可】

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