Buffer-enhanced electron injection in organic light-emitting devices with copper cathode
2013 (English)In: Organic electronics, ISSN 1566-1199, Vol. 14, no 2, 511-515 p.Article in journal (Refereed) Published
We explore in this work the use of Cu as a cathode material in organic light-emitting devices (OLEDs) and find a dual electron–injection enhancement mechanism derived from the LiF layer. Different from what observed previously in Ag- and Au-cathode devices, the LiF buffer layer in the Cu-cathode OLEDs starts to play its role in performance improvement when it is much thinner than 3 nm, the optimal value of buffer thickness, and in the case of optimal thickness, the device exhibits excellent performance comparable to conventional Al-cathode device. The phenomenon observed is ascribed to enhanced electron injection as a result of combined effect of interfacial reaction and tunneling barrier reduction mechanism: while chemical reaction plays a key role at the very beginning of interface formation, tunneling dominates in the subsequent stage leading to the tremendous improvement of the characteristics.
Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2013. Vol. 14, no 2, 511-515 p.
Interface modification; Cu cathode; Composited mechanism; Organic light-emitting devices; Energy level alignment
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:liu:diva-108498DOI: 10.1016/j.orgel.2012.11.017ISI: 000314658700012OAI: oai:DiVA.org:liu-108498DiVA: diva2:730581