ANALYSIS OF LIGHT-EMITTING-DIODES BY X-RAY REFLECTIVITY MEASUREMENTS

X-ray reflectivity investigations were performed on organic light emit ting diodes (LEDs) with the purpose of characterizing those properties which control the performance of the devices. These are the thickness of the electrodes and of the active organic films. the roughness of t he layers and of the substrate, as well as the internal structure of t he organic films. Based on the experimental results and corresponding simulations on multilayer polymer/metal structures, it has become obvi ous that X-ray reflectometry constitutes anon-destructive technique fo r characterizing light emitting diodes with a complex multilayer archi tecture. (C) 1997 Elsevier Science S.A.