Efficiency enhancement in organic photovoltaic cell with interpenetrating conducting polymer/C60 heterojunction structure by substrate-heating treatment

The effect of heat treatment during evaporation Of C-60 on the characteristics of a photovoltaic cell with a structure of indium-tin-oxide (ITO)/C-60/poly(3-hexylthiophene) (PAT6)/Au was studied. The C60 films were fabricated on the substrates at different temperatures and the C-60/PAT6 heterojunction of this photovoltaic cell was fabricated by spin-coating the solution of PAT6 onto the C60 thin film formed on ITO. Heating the substrate caused a marked increase in the short-circuit current and in the external quantum efficiency (EQE); these were discussed by taking the morphology and carrier mobility of the C60 thin film fabricated by this method into consideration.