A process for producing a stack of a first electrode/active layer/second electrode, which stack is intended for an electronic device, in particular an organic photodetector or an organic solar cell, the process comprises the following steps: (a) depositing a first conductor layer on the front side of a substrate, in order to form the first electrode; and (b) depositing an active layer taking the form of a thin organic semiconductor layer, this layer including discontinuous zones; wherein this process further comprises the following steps: (d) depositing a resist layer on that side of the stack which is opposite the substrate, which is at least partially transparent; (e) exposing the resist layer via the back side of the substrate; (f) developing the resist layer; and (g) depositing a second conductor layer in order to form the conductive second electrode.