75‐1: Real Time Doping Management of High‐Performance Organic Electroluminescence Displays

Recently, organic light emitting diode (OLED) and quantum dot (QD)‐OLED displays are attracting attention as representative displays ranging from mobile to tablet, laptop, and TV markets. In these OLED and QD‐OLED displays, the individual thickness and doping ratio of functional multilayer films of organic electroluminescence (EL) are the most important factors in device characteristics such as color coordinates, efficiency, and lifetime. In particular, unlike the thickness that can be measured up to the sub‐nanometer, quantified measurement methods have not been well prepared for the various dopant contents of EL. We proposed a method to quantify the doping ratio of individual functional thin films of EL using Raman spectroscopy. First, a unique signal of each layer material of the EL was found using Raman spectroscopy, and a significant signal was classified from the resultant signal. And by utilizing the intensity of the peak of the signal, we succeeded in quantifying the doping rate using partial least squares regression and artificial intelligence. In particular, quantification was very successful even in the thinnest thin film and the thin film with the lowest dopant content. Finally, as a result of evaluation by dividing the doping rate of the EL light emitting layer in the pixel of the actually completed OLED sample by dividing it from 0 to 6%, the linear regression of the average doping rate converged to 100% was obtained. Accordingly, it succeeded in real‐time monitoring and management of the doping ratio of the EL element, which is a major factor influencing the performance and quality of OLED and QD‐OLED displays, in mass production.