Conjugated Polyelectrolyte Hybridized ZnO Nanoparticles as a Cathode Interfacial Layer for Efficient Polymer Light‐Emitting Diodes. (10th November 2015)

• Record Type: Journal Article
• Authors: Kim, Kyungmok; Suh, Minwon; Choi, Jihae; Lee, Dongchan; Kim, Youngsun; Cheong, Sang Hun; Kim, Donghyuk; Jeon, Duk Young
• Is Part Of: Advanced functional materials. Volume 25:Number 48(2015)
• Page Start: 7450
• Page End: 7456
• Publication Date: 2015-11-10
• Subjects: zinc oxide nanoparticles -- conjugated polyelectrolytes -- cathode interfacial layers -- organic–inorganic hybrid materials -- polymer light‐emitting diodes; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201502360
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract : Alkoxy side‐chain tethered polyfluorene conjugated polyelectrolyte (CPE), poly[(9, 9‐bis((8‐(3‐methyl‐1‐imidazolium)octyl)‐2, 7‐fluorene)‐alt‐(9, 9‐bis(2‐(2‐methoxyethoxy)ethyl)‐fluorene)] dibromide (F8imFO4 ), is utilized to obtain CPE‐hybridized ZnO nanoparticles (NPs) (CPE:ZnO hybrid NPs). The surface defects of ZnO NPs are passivated through coordination interactions with the oxygen atoms of alkoxy side‐chains and the bromide anions of ionic pendent groups from F8imFO4 to the oxygen vacancies of ZnO NPs, and thereby the fluorescence quenching at the interface of yellow‐emitting poly( p ‐phenylene vinylene)/CPE:ZnO hybrid NPs is significantly reduced at the CPE concentration of 4.5 wt%. Yellow‐emitting polymer light‐emitting diodes (PLEDs) with CPE(4.5 wt%):ZnO hybrid NPs as a cathode interfacial layer show the highest device efficiencies of 11.7 cd A −1 at 5.2 V and 8.6 lm W −1 at 3.8 V compared to the ZnO NP only (4.8 cd A −1 at 7 V and 2.2 lm W −1 at 6.6 V) or CPE only (7.3 cd A −1 at 5.2 V and 4.9 lm W −1 at 4.2 V) devices. The results suggest here that the CPE:ZnO hybrid NPs has a great potential to improve the device performance of organic electronics. Abstract : High‐efficiency polymer light‐emitting diodes (11.7 cd A −1 at 5.2 V and 8.6 lm W −1 at 3.8 V) are demonstrated using F8imFO4 conjugated polyelectrolyte (CPE)‐hybridized zinc oxide nano­particles (ZnO NPs) as a cathode interfacial layer. The alkoxy sidechains and bromide anions of F8imFO4 form a coordination bond to the ZnO surface, thus reducing fluorescence quenching of light‐emitting polymer.