XRD patterns of CSA doped polypyrrole nanostructure and silver-polypyrrole nanocomposites.
High resolution TEM image of the samples: (a) and (b) pure CSA doped polypyrrole at different magnifications; (c) SAD pattern of Fig. 2(a) ; (d) and (e) Silver-polypyrrole nanocomposite with 0.02 M AgNO3 at different magnifications; (f) SAD pattern of Fig. 2(e) ; (g) and (h) Silver-polypyrrole nanocomposite with 0.04 M AgNO3 at different magnifications; (i) SAD pattern of Fig. 2(g) .
TGA curves of CSA doped polypyrrole nanostructure and silver/ polypyrrole nanocomposites, respectively, obtained under nitrogen atmosphere at a heating rate of 10 °C/min.
Temperature dependent relative permittivity of all the samples obtained from the measured value of capacitance at 1 kHz frequency.
J–V characteristics of CSA doped polypyrrole nanostructure and silver/polypyrrole nanocomposites, respectively, in the temperature range 303–143 K, plotted in log-log scale.
Current density (J) in the forward and backward sweep of voltage (V) in the linear scale at room temperature for different samples, showing symmetric J–V characteristics with the presence of charge trapping within the measured voltage range. Inset shows the same variation in the log-log scale.
Calculated electric field and temperature dependent mobility for allthe samples. Solid lines are best fits of the data by Poole-Frenkel law [Eq. (4) ].
Power law dependent plots of current densities within the measured electric field, for different samples at different temperatures. Solid lines are best fits of the data by Poole-Frenkel law [Eq. (4) ].
(a) Temperature dependency of zero field mobility “μ0” and effective zero field mobility “θμ0” for different samples as shown in the figure. Inset shows the variation of the fraction of free charge carriers “θ” with temperatures. Solid lines are best fits to Eq. (3) to get the activation energies as shown at the inset. (b) Variation of “γ” obtained from PF fits of different data (Figs. 7 and 8 ). Solid lines are best fits to Eq. (6) .
Temperature variation of the characteristic energy Et. Inset shows the above variation for the slope l (m-1) obtained from the J–V characteristics (Fig. 5(a) ).
Schematic representation of localized trap states within the HOMO and LUMO band before and after the incorporation of silver nanoparticles within the polypyrrole matrix. EF and Et are the Fermi level and trap energy level, respectively.
Variation of zero field mobility “μ0” with temperature. Based upon temperature dependence of “μ0 ,” two regions viz. PF (Arrhenius) and VRH (nonlinear) have been identified (marked by thick solid curves). Solid lines are best fits to Eqs. (5) and (13) , respectively.
Room temperature zero field mobility “μ0” and parameters, obtained from the fitting of temperature dependent “μ0” by Poole Frankel and Variable range hooping conduction mechanism for different samples.
Article metrics loading...
Full text loading...