A device comprising a number of different wavelength-selective active-layers arranged in a vertical stack, having band-alignment and work-function engineered lateral contacts to said active-layers, consisting of a contact-insulator and a conductor-insulator. Photons of different energies are selectively absorbed in or emitted by the active-layers. Contact means are arranged separately on the lateral sides of the vertical stack for injecting charge carriers into the photon-emitting layers and extracting charge carriers generated in the photon-absorbing layers. The device can be used for various applications for light emission or light absorption. The stack of active layers may also include top and bottom electrodes whereby the device can also be operated as a FET device.