A method of fabrication of an array of optoelectronic structures includes first providing a crystalline substrate having cells corresponding to individual optoelectronic structures to be obtained. Each of the cells includes an opening to the substrate. Then, several first layer portions of a first compound semiconductor material are grown in each the opening to at least partly fill a respective one of the cells and form an essentially planar film portion therein. Next, several second layer portions of a second compound semiconductor material are grown over the first layer portions that coalesce to form a coalescent film extending over the first layer portions. Finally, excess portions of materials are removed, to obtain the array of optoelectronic structures. Each optoelectronic structure comprises a stack protruding from the substrate of: a residual portion of one of the second layer portions; and a residual portion of one of the first layer portions.