An organic light-emitting diode, organic solar cell or switching element comprising at least one substituted carbazole derivative of the general formula (I), (II) or (III) in which X is NR4, O, S or PR4; Y is NR5, O, S or PR5; where at least one of the symbols X and Y is NR4 or NR5; substituted carbazole derivatives of the formula (I), (II) or (III); a light-emitting layer comprising at least one substituted carbazole derivative of the general formula (I), (II) or (III) and at least one emitter material; the use of substituted carbazole derivatives of the general formula (I), (II) or (III) as matrix material, hole/exciton blocker material and/or electron/exciton blocker material and/or hole injection material and/or electron injection material and/or hole conductor material and/or electron conductor material in an organic light-emitting diode, an organic solar cell or in a switching element, and a device selected from the group consisting of stationary visual display units, mobile visual display units, illumination units, keyboards, garments, furniture and wallpaper comprising at least one inventive organic light-emitting diode.