Temperature measurements of the PEDOT-PSS layer in a polymer light-emitting diode by stokes and anti-stokes Raman scattering

We have observed Stokes and anti-Stokes Raman scattering from an operating double-layer polymer light-emitting diode fabricated with poly(3,4-ethylenedioxythiophene)-poly(4-styrenesulfonate) (PEDOT-PSS) as a hole-injection layer (50 nm thickness) and a polyfluorene-based polymer blend as a light-emitting layer (90 nm thickness) with excitation at 633 nm. The temperature of the PEDOT-PSS layer was estimated to be 74 +/- 6 degrees C at a current of 150 mA/cm(2) (1000 cd/m(2)), whereas that of the glass surface measured by a thermocouple was 41 degrees C. (C) 2008 Elsevier B.V. All rights reserved.