摘要
Frequency-dependent electrical transport properties of 4,4′,4″-tri(N-carbazolyl)-triphenylamine(TCTA)are analyzed by impedance spectroscopy(IS)as functions of bias and temperature.The Cole-Cole plot shows a single semicircle which indicates that the equivalent circuit can be designed as a single parallel resistor R_(p)and capacitor C_(p)network with a series resistance R_(s).The bulk capacitance C_(p)remains unchanged while the resistance R_(p)decreases along with bias voltage.Conduction mechanism matches well with the space-charge-limited current(SCLC)model with exponential trap charge distributions.The temperature-dependent impedance studies reveal the activation energy of 0.246eV with no phase change in the temperature range 220-320K.These results indicate that the IS method is applicable for organic semiconductors having a wide band gap.
作者
LI Bi-Xin
CHEN Jiang-Shan
ZHAO Yong-Biao
MA Dong-Ge
李必鑫;陈江山;赵勇彪;马东阁(State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022;Graduate University of Chinese Academy of Sciences,Beijing 100049)
基金
Supported by the Science Fund for Creative Research Groups of NSFC(20921061)
the National Natural Science Foundation of China(50973104,60906020)
the National Basic Research Program of China under Grant Nos 2009CB623604 and 2009CB930603
the Foundation of Jilin Research Council(20080337,20090127)。
