Influence of graphene on the structural and electrical properties of PCDTBT polymer

摘要

Structural evolution and electrical and dielectrical properties of hybrid structures based on PCDTBT: graphene nanocom-posite were reported. The insertion of the graphene layers into the PCDTBT matrix is proved by the analysis of the Raman and the XRD curves obtaining for the PCDTBT: graphene hybrid nanocomposite. In fact, the Raman spectrum of PCDTBT: graphene nanocomposites shows the appearance of a new peak in 1620 nm position corresponds to the G-band of graphene. The effect of adding different weight ratios of graphene layers added (1.5,2, and 2.5 wt%) into PCDTBT matrix on electrical properties was discussed in dark condition. The electrical parameters such as the ideality factors (n), the barrier height (φb), and the series resistance (R_s) were calculated. The charge transport was evaluated by space-charge-limited conduction mechanism. The dielectrical behavior shows a strong effect of graphene addition. It increases the trap state density (N_(SS)). Moreover, a relaxation peak appeared in the imaginary parts of impedance (Z") in the range of (m_s) indicating a dipolar relaxation type.