Prepering schottky barrier diodes (SBDS) with organic interface and investigating their elektrical and dielectric properties in a wide frequency range

Au/PPy/n-Si Schottky barrier diodes SBDs were fabricated by forming polypyrrole (PPy) organic layer on n-Si using the organic evaporating technique. Frequency dependent dielectric constant (ε'), dielectric loss (ε''), loss tangent (tanδ), real and imaginary parts of electrical modulus (M' and M'') and AC electrical conductivity (σac) parameters of the structure were investigated in the frequency range of 10kHz-500kHz. It was found that the values of the ε', ε'' and tanδ, in general, decrease with increasing frequency while an increase is observed in σac, M' and M''. The tanδ and M'' also exhibit a peak at about zero-bias voltage while peak intensity weakens with increasing frequency. The values of ε' and M' decrease with increasing voltage while an increase is observed in ε'', tanδ, σac and M''. These changes in ε', ε'', tanδ, M', M'' and σac values was attributed to surface charge polarization and the particular density distribution of surface states localized at PPy/n-Si interface.