An optoelectronic device (40; 90; 95; 100; 105) comprising: a support ; blocks of a semiconductor material, resting on the support and each comprising a first surface on the side opposite to the support and lateral walls ; a nucleation layer on each first surface; a first electrically-insulating layer covering each nucleation layer and comprising an opening exposing a portion of the nucleation layer, for each block , the assembly comprising the block , the nucleation layer , and the first electrically-insulating layer being included in a pedestal ; a semiconductor element resting on each first insulating layer and in contact with the nucleation layer covered with said first insulating layer in the opening; a shell covering each semiconductor element and comprising an active layer capable of emitting or of absorbing an electromagnetic radiation; a second electrically-insulating layer covering at least a lower portion of each semiconductor element and extending over the lateral walls of each pedestal and over a lower portion of the shell ; a first electrically-conductive layer , at least partly transparent to said radiation and covering each shell and the portion of the second electrically-insulating layer extending over the shell , the second electrically-insulating layer being located between the shell and the first electrically-conductive layer ; and a second electrically-conductive layer , reflecting said radiation, extending between the semiconductor elements, extending over at least a portion of the lateral walls of the blocks, and extending over the first electrically-insulating layer , the first electrically-insulating layer being located between the second electrically-conductive layer and the second electrically-insulating layer , which second conductive layer does not cover the shells . a support ; blocks of a semiconductor material, resting on the support and each comprising a first surface on the side opposite to the support and lateral walls ; a nucleation layer on each first surface; a first electrically-insulating layer covering each nucleation layer and comprising an opening exposing a portion of the nucleation layer, for each block , the assembly comprising the block , the nucleation layer , and the first electrically-insulating layer being included in a pedestal ; a semiconductor element resting on each first insulating layer and in contact with the nucleation layer covered with said first insulating layer in the opening; a shell covering each semiconductor element and comprising an active layer capable of emitting or of absorbing an electromagnetic radiation; a second electrically-insulating layer covering at least a lower portion of each semiconductor element and extending over the lateral walls of each pedestal and over a lower portion of the shell ; a first electrically-conductive layer , at least partly transparent to said radiation and covering each shell and the portion of the second electrically-insulating layer extending over the shell , the second electrically-insulating layer being located between the shell and the first electrically-conductive layer ; and a second electrically-conductive layer , reflecting said radiation, extending between the semiconductor elements, extending over at least a portion of the lateral walls of the blocks, and extending over the first electrically-insulating layer , the first electrically-insulating layer being located between the second electrically-conductive layer and the second electrically-insulating layer , which second conductive layer does not cover the shells . <EOS>