Determination of conduction parameters of vacuum deposited magnesium phthalocyanine thin films from their electrical, optical studies and application of VRH model

Sandwich and planar structures are fabricated using magnesium phthalocyanine (MgPc) as active layer and gold (Au) as electrodes by thermal evaporation method. The permittivity ε is determined from the dependence of capacitance on film thickness. J-V characteristics of Au/MgPc/Au structure at room temperature are performed. Thermally generated hole concentration p0, hole mobility μp, total trap concentration Nt and depth of the trap level are estimated. The activation energies are determined from the Arrhenius plots of ln σ versus 1000/T. Employing the variable range hopping model, hopping conduction parameters of the material are calculated. The absorption spectrum of MgPc thin film deposited at room temperature is recorded in the spectral range 300-900 nm. The optical band gap of MgPc thin film is determined from the α2 versus hν graph.