P‐260: Late‐News Poster: Doping Ratio Control of Organic Composite Layer in OELDs by Spectroscopic Ellipsometry

The OLEDs industry needs a reliable nondestructive process control method for measuring the correct thickness of layers and estimation of doping or mixing ratio. Using spectroscopic ellipsometry, we applied for thickness and doping ratio monitoring for emission layer (EML) and mixed electron transport layer (mETL) grown on glass by evaporator. Optical properties of EML host and dopant, mETL host and mixing material have been investigated. We present the effect of doping on optical constants dispersions of EML and mETL layers in the photon energy range 1.2 to 5.0 eV. We adopted the Effective Medium Theory (EMT) to monitoring mixing ratio and dispersion equation to monitoring doping ratio. In result developed monitoring tool can measure imperceptible difference doping ratio.