Conjugated Polyelectrolyte Blend with Polyethyleneimine Ethoxylated for Thickness-Insensitive Electron Injection Layers in Organic Light-Emitting Devices.
ACS Appl Mater Interfaces
; 10(20): 17318-17326, 2018 May 23.
Article
in En
| MEDLINE
| ID: mdl-29714996
ABSTRACT
Electron injection layers (EILs) based on a simple polymer blend of polyethyleneimine ethoxylated (PEIE) and poly[(9,9-bis(3'-(( N, N-dimethyl)- N-ethylammonium)-propyl)-2,7-fluorene)- alt-2,7-(9,9-dioctylfluorene)] (PFN-Br) can suppress the dependence of organic light-emitting device (OLED) performance on thickness variation compared with single PEIE or PFN-Br EILs. PEIE and PFN-Br were compatible with each other and PFN-Br uniformly mixed in the PEIE matrix. PFN-Br in PEIE formed more fluorene-fluorene pairs than PFN-Br alone. In addition, PEIEPFN-Br blends reduced the work function (WF) substantially compared with single PEIE or PFN-Br polymer. PEIEPFN-Br blends were applied to EILs in fluorescent polymer-based OLEDs. Optimized PEIEPFN-Br blend EIL-based devices presented lower driving voltages and smaller dependences of device performance on EIL thickness than single PEIE or PFN-Br-based devices. These improvements were attributed to electron-transporting fluorene moieties, increased fluorene-fluorene pairs working as channels of electron transport, and the large WF reduction effect of PEIEPFN-Br blends.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
ACS Appl Mater Interfaces
Journal subject:
BIOTECNOLOGIA
/
ENGENHARIA BIOMEDICA
Year:
2018
Document type:
Article