Dielectric response of polyaniline derivatives and its effect on the absorption spectrum of modified copper phathlocyanine

Abstract

The dielectric constant of polyaniline (PANI) derivatives, were investigated over the frequency range from 20 Hz to 1 MHz. The dielectric constant for PANI-base and PANI-salt pellets was decreasing as the frequency increasing. The PANI-salt dielectric constant recorded a huge value of > 108 at 20 Hz, and 104 at 1 MHz. The PANI-base dielectric constant recorded ~11 at 20 Hz and ~3.5 at 1 MHz. Their dielectric loss, dielectric loss tangent and ac conductivity were investigated as well. Optical absorption for PANI derivatives in a solution and thin film states were studied. The effect of the PANI-salt's dielectric property in solution and thin film states on the absorption spectrum of modified copper phathlocyanine with sulfonic acid group (CuPc_TS) has been studied. We observed an enhancement of the absorption spectrum of the CuPc_TS to become more broadness and reached the red region of the spectrum compared to the absorption spectrum of CuPc_TS alone. We attributed the more broadness of the CuPc_TS spectrum to the improvement of the CuPc_TS relative permittivity.