C-60 was introduced as a modifier on indium tin oxide (ITO) and the effect of C-60 modification on light-emitting efficiency of blue organic light-emitting didoes was investigated. Device performances of C-60 modified devices were greatly dependent on ITO surface properties and C-60 thickness. Power efficiency of blue devices was improved by 80% by C-60 buffer layer on ITO because of low driving voltage and balanced electron-hole recombination (c) 2007 The Electrochemical Society.