Low electrode induced optical losses in organic active single layer polyfluorene waveguides with two indium tin oxide electrodes deposited by pulsed laser deposition

We demonstrate that 20 nm thick indium tin oxide (ITO) layers deposited by pulsed laser deposition present sheet resistance as low as 130 Omega/square and very uniform morphology, with an average roughness of about 0.4 nm, and peak-to-valley roughness as low as 8.2 nm. This good uniformity allowed us to realize a single layer polyfluorene active waveguide with both top and bottom ITO electrodes showing clear amplified spontaneous emission and electrode induced losses as low as 3.0 cm(-1). We investigated the effects of hole injection in the ASE intensity concluding that complete gain suppression due to polaron absorption would take place for current density of about 360 mA cm(-2). (c) 2006 American Institute of Physics.