The present invention relates to a photosensitive organic semiconductor composition comprising an organic p-type semiconductor pigment with a p-type conducting polymer, wherein the ionization potentials of the organic p-type semiconductor pigment and the p-type conducting polymer are nominally equivalent and a photosensitive organic semiconductor composition comprising an organic n-type semiconductor pigment with an n-type conducting polymer, wherein the electron affinities of the organic semiconductor pigment and the conducting polymer are nominally equivalent. The present invention also relates to a p/n heterojunction utilizing the photosensitive organic semiconductor compositions.