Exponential trap distributions of carriers in noncrystalline films of P1-2xNa1-2xO3-4xPbx (x = 0, 0.15 and 0.3) for electronic applications

Films of P1-2xNa1-2xO3-4xPbx (x = 0, 0.15 and 0.3) were fabricated. Their structural and electrical properties were investigated. X-ray diffraction analysis confirms the amorphous nature of these films. Scanning electron microscopy images show that the increase in Pb content enhances the smoothness of the films. Moreover, the electrical measurements were recorded in the temperature range of 298–423 K. The obtained results show that the conductivity is thermally activated, having two conduction mechanisms with activation energies of 0.052 ± 0.006 and 0.56 ± 0.08 eV below and above 339 K, respectively. Two regions appear in the experimental results of current–voltage characteristics. The Ohmic region shows that the conduction has no electron traps in the forbidden gap. Moreover, the charge carrier’s mobility is enhanced from 1.69 × 10−10 to 137.39 × 10−10 cm2 V−1 S−1 due to the increasing content of Pb. On the other hand, at the high-voltage region, a limited space charge is expected to be controlled by exponential trap distributions of carriers. Therefore, the traps concentration increases due to the increase in Pb content.