There is described an optoelectronic device where each light-emitting diode has a wire-like shape. Spacing walls are formed so that the lateral sidewalls of each light-emitting diode are surrounded by at least one of the spacing walls. Light confinement walls directly cover the lateral sidewalls of the spacing walls by being in contact with the latter. The spacing walls have a convex-shaped outer face. At least one of the spacing walls has, over a lower portion, a thickness that increases when getting away from the substrate. They have, over an upper portion, a thickness that decreases at the level of the upper border of the light-emitting diode when getting away from the substrate. The light confinement walls have an inner face having a concave shape matching with the convex shape and directed towards the light-emitting diode for which it confines the light radiation thereof.