Electric field and temperature dependence of hole mobility in electroluminescent PDY 132 polymer thin films

Abstract

The current density-voltage (J - V) behavior of polymer PDY 132 thin films has been investigated in hole-only device configuration, viz., ITO/poly(ethylene-dioxthiophene):polystyrenesulphonate (PEDOT:PSS)/PDY 132/Au, as a function of polymer (PDY) film thickness (150 nm and 200 nm) and temperature (290-90 K). Hole current density was found to follow two distinct modes of conduction, (i) low electric field region I: ohmic conduction where slope ∼ 1, and (ii) intermediate and high electric field region II: non ohmic conduction where slope ∼ 2. Region I has been attributed to the transport of intrinsic background charge carriers while region II has been found to be governed by space charge limited currents (SCLC) with hole mobility strongly dependent on electric field and temperature. The respective hole transport parameters determined from the SCLC regime, μp 0 is 3.7 × 1 0- 3 m2 / V s, μp (0, T) is 3.7 × 1 0- 8 m2 / V s, and zero field activation energy (Δ0) of 0.48 eV is obtained. © 2010 Elsevier Ltd. All rights reserved.