A photovoltaic semiconductor junction device which is particularly useful as a solar cell comprises a first layer of organic semiconductor material exhibiting one type of electronic conductivity and a second of inorganic semiconductor material having the same or opposite type conductivity. The first layer of organic semiconductor material has an energy bandgap relatively wider than that of the second layer of semiconductor material. The electron affinities of the first and second layers of semiconducting material may be equal, greater, or less than those of the other.The first layer of organic semiconductor material must either be doped to have a resistivity below 10.sup.6 ohm-centimeters or be sufficiently thin to allow conduction. In devices employing n-type layers on p-type substrates, the conduction band energy level of the organic material is preferably at substantially the same energy level as the conduction band energy level of the narrower band gap semiconductor material. In devices employing p-type layers, the valence band energy level of the organic material is preferably at substantially the same energy level as the valence band energy level of the narrower bandgap inorganic semiconductor material.