Abstract: A device for the conversion of infrared radiation into another form of radiation of energy greater than that of the infrared radiation comprises a multilayer semiconductor structure (4) comprising at least two layers in which an electron gas and a gas of holes which are regenerated in the course of the use of the device are combined. There is at least one delocalized electron state in the structure, at an energy greater than the energy of the ground state of the electron gas, the difference between these energies being within the infrared range. When the structure is illuminated at a non-normal incidence by radiation (10), the energy of which is equal to this difference, the structure emits a radiation (14) of greater energy, by radiative recombination involving the holes. The device finds suitable application in infrared imaging systems.