A method of manufacturing nanowires (104) is provided, according to which method the nanowires are prepared by anodic etching a semiconductor substrate (10) with an alternating current density, so as to create first regions (4) and second regions (5) with different diameters. Thereafter, the diameters are reduced by preferably repeated oxidation and etching. Finally, the nanowires (104) are dispersed in a dispersion by ultrasonic vibration, through which the coupled nanowires split into individual nanowires of substantially uniform length. The nanowires may then be provided with a surface layer of a suitable material, for instance a luminescent material.