http://dx.doi.org/10.1016/j.optmat.2014.11.046">
 

Document Type

Journal Article

Department/Unit

Department of Physics

Title

Study of triplet exciton’s energy transfer in white phosphorescent organic light-emitting diodes with multi-doped single emissive layer

Language

English

Abstract

© 2014 Elsevier B.V. All rights reserved. The performance of three color single emissive layer white phosphorescent organic light-emitting diodes (PHOLEDs), with different hole transporting materials of N,N′-diphenyl-N,N′-bis(l-naphthyl-phenyl)-(l,l′-biphenyl)-4,4′-diamine (NPB), 4,4-,4-tris-N-carbazolyl-tri-Phenylamine (TCTA) and 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC), was analyzed. It is found that the luminous efficiency of white PHOLEDs is closely related to the triplet exciton energy level in the hole transporting layer (HTL). White PHOLEDs with a TAPC as HTL, having the highest triplet exciton energy level amongst the three different hole transporting materials, yielded external quantum efficiency of 25.5% at 4.5 V and a high luminous efficiency of 51 cd/A at 4.5 V with CIE color coordinates of (0.34, 0.39) at 10 V. The results reveal that the effective confinement of triplet excitons in white PHOLEDs with a high triplet exciton energy level HTL (TAPC) allows improving the luminous efficiency, as compared to the devices made with NPB and TCTA. Additionally, we demonstrated possibility for the loss of intensity in EL spectra of the white PHOLED devices with NPB and TCTA as HTL compared to that of the device with TAPC as HTL.

Keywords

Hole transporting layer, NPB, Single emissive layer, TAPC, TCTA, White PHOLED

Publication Date

2015

Source Publication Title

Optical Materials

Volume

40

Start Page

57

End Page

62

Publisher

Elsevier

ISSN (print)

09253467

ISSN (electronic)

18731252

This document is currently not available here.

Share

COinS