Luminescence and Electrical Conductivity of Polyamide Acid and Its Metal–Polymer Complexes with La and Tb

Abstract

The photoluminescence and electrical properties of organic semiconductors of polyamide acid (PAA) and its complexes with lanthanides are investigated. On the addition of La and Tb to PAA, the emission intensity increases by 40%. No inherent bands of lanthanides are found in the emission spectrum. The current-voltage characteristics and the temperature dependence of the conductivity of PAA and its complexes are investigated for layers ranging from 40 to 0.1 μm in thickness. A specific feature of its electrical properties is a hysteresis of the temperature dependence of conductivity with an increase or decrease in temperature. A considerable deviation of the current-voltage characteristics from linearity, which is associated with injection currents, is observed for layers 0.1–0.2 μm thick. The breakdown voltage and limiting-current density for these layers are 3–8 V and (2−1) × 10−2 A/cm2, respectively. The obtained value of the current density is comparable with the current density in layers of electroluminescent conjugate polymers at the same voltages.