Nonlinear behavior in electrical properties of fully screen printed electroluminescent panels

Abstract

We study the influences of printing parameters of fully screen printed electroluminescent panels on frequency and voltage dependent electrical properties of these devices. Significant nonlinear electrical features as well as a sensitivity to external illumination were observed. By varying the number of subsequent wet-in-wet printing steps within the dielectric and the luminescent layers of the electroluminescent panel, we studied the capacitive and dissipative behavior of current transport in the device. We used a novel method of high voltage impedance spectroscopy at frequencies between 10 Hz and 1 MHz with voltages up to 70 V_rms and compared measurements taken in dark and illuminated ambiences. We propose a qualitative model on the nonlinearity based on ferroelectric and semiconductive features of the dielectric layers as described by the Drude model.