Effect of molecular weight on the efficiency of poly(N-vinylcarbazole)-based polymer light-emitting diodes

TitleEffect of molecular weight on the efficiency of poly(N-vinylcarbazole)-based polymer light-emitting diodes
Publication TypeJournal Article
Year of Publication2011
AuthorsCai M, Xiao T, Chen Y, Hellerich E, Liu R, Shinar R, Shinar J
Journal TitleApplied Physics Letters
Volume99
Pages203302
Date Published11/14
ISBN Number0003-6951
Accession NumberISI:000297786500062
Keywordsdevices, LAYER
Abstract

Polymer light-emitting diodes based on poly(N-vinylcarbazole) (PVK) with molecular weights M(W) of 1.1 x 10(6) and similar to 7.5 x 10(4) are compared. For devices without an electron transport layer (ETL), the high M(W) PVK yields higher external quantum efficiency (0.67% vs 0.18%), but for devices with an ETL, the low MW PVK yields higher efficiency (1.13% vs 0.83%). This intriguing difference is believed to result from higher energetic disorder in the high M(W) polymer and different recombination zone-quenching metal electrode distances, in agreement with Konezny et al. [Appl. Phys. Lett. 97, 143305 (2010)]. (C) 2011 American Institute of Physics. [doi:10.1063/1.3659467]

URL<Go to ISI>://000297786500062
DOI10.1063/1.3659467
Alternate JournalAppl Phys Lett