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

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.

KEYWORDS:

• FDTD
• Light extraction
• OLED
• Photonic crystal
• Total internal reflection
• Triangular band structure

Acknowledgements

We express our sincere gratitude to the Principal, R.M.D Engineering College and thank all the teaching and non- teaching staff of Electronics and Communication Department, for their blessing and support throughout the dissertation.

Additional information

Notes on contributors

P. Santhoshini

P Santhoshini has been assistant professor in the Department of Electronics and Communication Engineering at RMD Engineering College since June 2014. She completed her BE degree in electronics and communication engineering in the year 2011 at C Abdul Hakeem College of Engineering and Technology, Affiliated to Anna University and ME degree in applied electronics at RMK Engineering College, affiliated to Anna University in the year 2013. She is pursuing PhD in Anna University in optical communication. She has 6.5 years of teaching experience in handling UG classes.

K. HelenPrabha

K Helen Prabha has been professor and head of the Department of Electronics and Communication Engineering at RMD Engineering College since January 2009. She obtained her BE degree in electronics and communication engineering from GCT, Bharathiar University, Coimbatore and ME degree in applied electronics from CIT, Bharathiar University, Coimbatore. She completed PhD degree in biomedical signal processing from Anna University, Chennai. She has 24 years of teaching experience and 15 years of research experience. She published three patents. She is a reviewer of national and international level conferences. She is a fellow member in IETE, IEI and Life member of ISTE, SDIWC, CSTA and SCIEI. Email: [email protected]