A tetraphenylporphinatonickel-based mesogenic compound 5,10,15,20-tetrakis(4-n-pentadecylphenyl)porphinatonickel(II)
(C15TPPNi) was synthesised and its mesomorphic
and photoconductive properties were investigated. The photoconductive properties
were compared with those of the metal-free compound. All measurements were
carried out for symmetrical ITO/C15TPPNi/ITO type cells
and steady-state currents in the constant temperature conditions were detected.
A photocurrent rectification was seen in either the crystal phase or lamellar
mesophase of C15TPPNi. The metal-free compound with pentadecyl
chains showed a strong dependence of photocurrent rectification on mesomorphic
phases: the rectification is shown in the cell of crystal and low-temperature
lamellar phases and it disappears in the high-temperature lamellar mesophase.
This phenomenon was interpreted in terms of the various mechanisms of charged
carrier generation with the phase transition, based on the results of the
action spectra and the illumination light intensity dependence of the photocurrent.
The improvement of the contact for electric conduction at the interface upon
heating was found, which is a special feature of this mesomorphic phase in
the ITO/C15TPPNi/ITO cell in comparison with the metal-free
compound.
合成了一种基于四苯基卟吩
镍的介电性化合物 5,10,15,20-四(4-正
十五烷基苯基)卟吩
镍(II) (C15
TPPNi),并对其介电性和光电导特性进行了研究。光导特性与无
金属化合物的光导特性进行了比较。所有测量都是在对称的 ITO/C15
TPPNi/ITO 型电池中进行的,并检测了恒温条件下的稳态电流。 在 C15
TPPNi 的晶体相或片状介相中都出现了光电流整流现象。带有
十五烷基链的无
金属化合物显示出光电流整流对介质相的强烈依赖性:在晶体相和低温层状介质相的电池中显示出整流,而在高温层状介质相中整流消失。
根据光电流的作用光谱和照明光强依赖性的结果,从相变产生带电载流子的各种机制的角度解释了这一现象。 研究发现,与无
金属化合物相比,ITO/C15
TPPNi/ITO 电池中的介观相在加热时改善了界面上的导电接触,这是介观相的一个特点。