Modelling and optimization of OLED device layers through Monte Carlo simulation

Achieving higher luminous efficiency is a major concern in organic light emitting diodes (OLEDs). Diverse approaches, such as introduction of new material, altering device architecture, and implementing host–guest systems, are employed to attain higher luminous efficiency. The mechanism of photon transport inside different layers of various mediums and how it can affect or aid the luminous efficiency is not clearly investigated in many research studies undertaken so far. In this work, Monte Carlo simulation is used to understand the transport of a photon in three-layer OLED device model. Here, the impact of thicknesses of the electron transport layer (ETL), hole transport layer (HTL) and emissive layer (EML) on the photon transport is explored. It is observed that the percentage of photons absorbed, reflected and transmitted depends on the thickness of the layers above and beneath the EML. To have maximum transmittance at the anode end, the thickness of the EML, HTL and ETL layers are optimized as 30 nm, 35 nm and 40 nm respectively for this 3-layer OLED device.