An organic ambipolar light emitting field effect transistor having an architecture with layers stacked one over the other, adapted to generate a diffused illumination, comprises: a gate electrode, a dielectric layer superposed to said gate electrode, an ambipolar channel superposed to said dielectric layer, comprising a P-type semiconductor layer whose energy band is determined by its highest occupied molecular orbital HOMO-SCp and lowest unoccupied molecular orbital LUMO-SCp, a N-type semiconductor layer whose energy band is determined by its highest occupied molecular orbital HOMO-SCn and lowest unoccupied molecular orbital LUMO-SCn and a light emitting layer adapted to allow recombination of charge carriers of opposite sign, interposed between said P-type semiconductor layer and said N-type semiconductor layer, whose energy band is determined by its highest occupied molecular orbital HOMO-R and lowest unoccupied molecular orbital LUMO-R, respectively; a source electrode adapted to inject charges of a first type and a drain electrode adapted to inject charges of a second type, said source electrode and drain electrode being in contact with a same layer of said P-type or N-type semiconductor layers, the other of said semiconductor layers being in contact with the dielectric layer.