The invention relates to an organic photoactive device, especially an organic photovoltaic cell, with a contact and a countercontact as well as with an organic region that is electrically connected to the contact and the countercontact, wherein a photoactive region with a photoactive bulk heterojunction or a flat heterojunction between an electron-conducting organic material and a hole-conducting organic material is formed in the organic region and wherein the hole-conducting organic material and/or the electron-conducting organic material is formed from oligomers according to any one of the following types: conjugated acceptor-donor-acceptor oligomer (A-D-A' oligomer) with an acceptor unit (A) and a further acceptor unit (A') that are each connected to a donor unit (D), and conjugated donor-acceptor-donor oligomer (D-A-D' oligomer) with a donor unit (D) and a further donor unit (D') that are each connected to an acceptor unit (A).