Inverted quantum dot light emitting diodes using polyethylenimine ethoxylated modified ZnO

Hong Hee Kim, Soohyung Park, Yeonjin Yi, Dong Ick Son, Cheolmin Park, Do Kyung Hwang, Won Kook Choi

Research output: Contribution to journalArticle

85 Citations (Scopus)

Abstract

Colloidal quantum dots (QDs) are an emerging class of new materials due to their unique physical properties. In particular, colloidal QD based light emitting diodes (QDLEDs) have been extensively studied and developed for the next generation displays and solid-state lighting. Among a number of approaches to improve performance of the QDLEDs, the most practical one is optimization of charge transport and charge balance in the recombination region. Here, we suggest a polyethylenimine ethoxylated (PEIE) modified ZnO nanoparticles (NPs) as electron injection and transport layer for inverted structure red CdSe-ZnS based QDLED. The PEIE surface modifier, incorporated on the top of the ZnO NPs film, facilitates the enhancement of both electron injection into the CdSe-ZnS QD emissive layer by lowering the workfunction of ZnO from 3.58 eV to 2.87 eV and charge balance on the QD emitter. As a result, this device exhibits a low turn-on voltage of 2.0-2.5 V and has maximum luminance and current efficiency values of 8600 cd/m2 and current efficiency of 1.53 cd/A, respectively. The same scheme with ZnO NPs/PEIE layer has also been used to successfully fabricate green, blue, and white QDLEDs.

Original languageEnglish
Article number8968
JournalScientific reports
Volume5
DOIs
Publication statusPublished - 2015 Mar

All Science Journal Classification (ASJC) codes

  • General

Fingerprint Dive into the research topics of 'Inverted quantum dot light emitting diodes using polyethylenimine ethoxylated modified ZnO'. Together they form a unique fingerprint.

  • Cite this