Fourier-transform infrared and electrical properties of magnesium phthalocyanine thin films

Department of Physics, Faculty of Education, Ain Shams University, Heliopolis Rorxy Square 11757, Cairo, Egypt

Corresponding author: prof_nahhas@yahoo.com

Received: 16 September 2010
Accepted: 18 January 2011
Published online: 13 April 2011

Abstract

The Fourier-transform infrared (FT-IR) spectra of magnesium phthalocyanine (MgPc) were investigated in the spectral range 500–4000 cm^-1. The spectra allow characterization of vibration modes. A comparison of absorption spectra of powder, as-deposited and annealed films is presented. The dark electrical resistivity measurements were carried out at different temperatures in the range 308 to 423 K. Two activation energies ΔE₁ = 0.23 eV and ΔE₂ = 0.69 eV were obtained. The thermal activation energy ΔE₁ is associated with impurity conduction and ΔE₂ is associated with intrinsic conduction. The current density-voltage characteristics of MgPc at room temperature showed a linear ohmic conduction mechanism at low voltages. At higher voltages the space-charge-limited conduction (SCLC) accompanied as a single dominant level. The temperature dependence of current density allows the determination of some essential parameters such as the hole mobility (μ_h), the trapping factor Θ and the total trap concentration (N_t).