The effect of C 60 doping on the electroluminescent performance of organic light-emitting devices

Abstract

Organic light-emitting devices (OLEDs) with the PVK hole transport layer were fabricated. The effect of C 60 doping in the hole transport PVK layer on the performance of the devices was investigated by changing the C 60 content from 0 to 3.0 wt%. The OLEDs had a structure of ITO\\PEDOT:PSS\\PVK:C 60 (0, 0.5, 1.0, 2.0, 3.0 wt%)\\AlQ\\LiF\\Al. The doping led to a higher conductivity in C 60-doped PVK layer and the hole mobility of PVK was improved from 4.5×10 −7 to 2.6×10 −6 cm 2/Vs with the doping concentration of C 60 changing from 0 to 3.0 wt%. Moreover, the doping led to a high density of equilibrium charges carriers, which facilitated hole injection and transport. Doping of C 60 in PVK resulted in efficient hole injection and low drive voltage at high luminance.