| abstract |
A photoactive device is provided. The device comprises a first electrode, a second electrode, a photoactive region disposed between the first electrode and the second electrode and electrically connected to these electrodes. The photoactive region further comprises an organic donor layer and an organic acceptor layer forming a donor-acceptor heterojunction. The mobility of holes in the organic donor region and the mobility of electrons in the organic acceptor region differ from each other by at least a factor of 100 times, and more preferably, by a factor of at least 1000 times. At least one of the mobility of holes in the organic donor region and the mobility of electrons in the organic acceptor region is greater than 0.001 cm 2 / V-sec, more preferably greater than 1 cm 2 / V-sec. This heterojunction can take many types, including planar heterojunctions, bulk heterojunctions, mixed heterojunctions, and hybrid plane-mixed heterojunctions. |