A method for guiding a driverless, multi-track vehicle along a predetermined path, which vehicle rolls on wheels separated from each other in the vehicle width direction, wherein the vehicle is steered by changing the torque applied to at least one of its wheels, such that it follows the predetermined path. A plurality of pathways extend between the fluid inlet channel and the fluid outlet channel. An n-type ohmic contact electrode and a p-type ohmic contact electrode are deposed on the front side of the LED. The first electrode covers and contacts the first surface.