Charge transport study of polymer light emitting diodes by impedance spectroscopy

Abstract

The transport properties of polymer blend have been investigated by using impedance spectroscopy (IS) and current density -voltage (J-V) measurements based on a single-layer structure of ITO/polymer/Al. Impedance spectroscopy measurements showed that the device can be simulated by an equivalent parallel R-C network with a contact resistance Rs in series, the resistance R decreases along with bias voltage. The variation of the whole conductance and capacitance of the device with frequency and bias can be understood by the carrier response and the transit time dependence on the bias in the polymer film. © 2012 SPIE.