FDTD Based Simulation of Light Extraction in OLED using Triangular Band Structure

Abstract

ABSTRACT In OLED, external light extraction shows very low efficiency due to total internal reflection, metal surface absorption and surface Plasmon coupling. The photonic crystal is a unique platform for controlling or modifying the light propagation and its properties such as transmission and absorption. The band structure of photonic crystal is mainly proposed for suppressing the spontaneous emission of light. In this work, the Finite Difference Time Domain (FDTD) mathematical modelling has been used to analyse the light extraction efficiency in the triangular band structure of OLED displays by measuring the Purcell factor. Due to the rectangular nature of FDTD solver region, it may be necessary to include multiple unit cells in the solver region for the triangular band structure. There is an improvement in the far-field intensity in OLED by optimizing the angular distribution of light through the substrate with the triangular band structure. Hence it can be widely used in ultra-compact optical devices.