Multi quantum well structures in deep blue organic light-emitting diode

¹  Department of Materials Science, Indian Association for the Cultivation of Science Jadavpur, Kolkata 700032, India
²  Institute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University 1, University Road, Tainan 701, Taiwan, ROC

Corresponding authors: cnssks@iacs.res.in yksu@mail.ncku.edu.tw

Received: 29 September 2008
Accepted: 21 November 2008

Abstract

Multi quantum well structures in the deep blue emitted system 2-methyl-9,10-di(1-napthyl)anthracene (α, α-MADN) are fabricated. The device structures are optimized with respect to the layer thickness and number of pairs forming the quantum wells. The Electroluminescence spectra are de-convoluted into 3 peaks with peak positions 432 nm, 458 nm and 500 nm, which are believed to arise due to the recombination of electrons and holes in the MADN, MADN/NPB interface and Alq₃, respectively. It is observed that a better confinement of excitonic charges in different layers causes the efficiency to enhance by more than 25% using optimized thickness parameters and 2 pairs of quantum well structures.