A method for activating and/or deactivating the phosphorescence of a structure is disclosed. The structure may include a first and a second material, wherein a phosphor is admixed with the first material and oxygen is present in the region of the phosphor. The second material may be oxygen-impermeable at an ambient temperature and, in the oxygen-impermeable state, act as an oxygen barrier between the first material and a surrounding environment. To activate the phosphorescence, in a first activation step, oxygen present in the structure is photochemically deactivated by irradiating the structure with light of a first characteristic, and, in a second activation step, the phosphorescence is activated by irradiating the structure with light of a second characteristic. To deactivate the phosphorescence, oxygen is introduced into the structure by heating the structure and/or by irradiating the structure with light of a third characteristic.