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 each layer or set
of layers having the same parameters for extracting charge carriers generated in
the photon-absorbing layers and/or injecting charge carriers into the photon-emitting
layers. The device can be used for various applications: wavelength-selective multi-spectral
solid-state displays, image-sensors, light-valves, light-emitters, etc. It can
also be used for multiple-band gap solar-cells. The architecture of the device
can be adapted to produce coherent light.
