Title: Enhancing the performance of organic-inorganic hybrid light-emitting diodes by inserting a conjugated polyelectrolyte interlayer

Authors: Yongli Wang; Qiaoli Niu; Donghuan Qin; Hongmei Liu; Yong Zhang

Addresses: Key Laboratory of Electroluminescent Devices of Guangdong Provincial Education Department, Institute of Optoelectronic Materials and Technology, South China Normal University, Guangzhou 510631, China ' Key Laboratory of Electroluminescent Devices of Guangdong Provincial Education Department, Institute of Optoelectronic Materials and Technology, South China Normal University, Guangzhou 510631, China ' Institute of Polymer Optoelectronic Materials and Devices Key Lab of Specially Functional Materials of Ministry of Education, South China University of Technology, Guangzhou 510640, China ' Institute of Polymer Optoelectronic Materials and Devices Key Lab of Specially Functional Materials of Ministry of Education, South China University of Technology, Guangzhou 510640, China ' Key Laboratory of Electroluminescent Devices of Guangdong Provincial Education Department, Institute of Optoelectronic Materials and Technology, South China Normal University, Guangzhou 510631, China

Abstract: Hybrid light-emitting diodes (HyLEDs) incorporating the advantages of organic and inorganic semiconductors, were promising to realise efficient electroluminescence with air-stable charge-injection interfaces. However, HyLEDs with only inorganic semiconductor such as zinc oxide (ZnO) as electron-injection layer suffered from low devices efficiencies due to large electron injection barrier. To improve the electron injection, conjugated polyelectrolyte poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) was used together with ZnO as electron-injection layer by fabricating it on top of ZnO. Experimental data showed that the light efficiencies of HyLEDs were almost doubled after the insertion of PFN. The performances enhancement was attributed to the reduced energy barrier for electron injection from ZnO. The electron current increased. And therefore, the balance of electron and hole currents was improved.

Keywords: hybrid LEDs; light emitting diodes; nanomanufacturing; ZnO; zinc oxide; heterojunction; conjugated polyelectrolyte; nanotechnology; organic semiconductors; inorganic semiconductors; electroluminescence; electron injection.

DOI: 10.1504/IJNM.2014.058997

International Journal of Nanomanufacturing, 2014 Vol.10 No.1/2, pp.56 - 63

Received: 20 Dec 2012
Accepted: 11 Mar 2013
Published online: 17 May 2014 *

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