Abstract
Tuning of the barrier parameters of n-type Schottky junctions formed in photovoltaic co-deposited films consisting of fullerene and α-sexithiophene (C60:6T) was demonstrated by ppm-level control of cesium carbonate (Cs2CO3) doping. Increases in the carrier concentration of electrons along with the overall doping concentration, which was observed by capacitance measurements and which affected cell performance, confirmed that Cs2CO3 acts as a donor dopant for C60:6T co-deposited films. The doping efficiency was determined to be around 0.15.