A light-emitting device (10; 40; 50; 60) comprising: an at least partially doped substrate of a first conductivity type, comprising a surface ; light-emitting diodes (DEL), each comprising at least one non-doped or doped three-dimensional semiconductor element of the first conductivity type, resting on said surface, in contact with said surface or separated from said surface by a seed pad ; and semiconductor regions forming photodiodes (PH), at least partially doped of a second conductivity type opposite to the first conductivity type and extending in the substrate from said surface between at least some of the three-dimensional semiconductor elements such that, for each three-dimensional semiconductor element, a portion of the substrate of the first conductivity type extends all the way to said surface in contact with the three-dimensional semiconductor element or with the seed pad on which the three-dimensional element rests; characterized in that the device comprises: an at least partially reflective layer covering the semiconductor regions between the three-dimensional semiconductor elements to avoid the semiconductor regions to receive a light radiation through the surface; an insulating layer interposed between the semiconductor regions and said at least partially reflective layer; and electrically-insulating regions extending along the lateral edges of at least some semiconductor regions . an at least partially doped substrate of a first conductivity type, comprising a surface ; light-emitting diodes (DEL), each comprising at least one non-doped or doped three-dimensional semiconductor element of the first conductivity type, resting on said surface, in contact with said surface or separated from said surface by a seed pad ; and semiconductor regions forming photodiodes (PH), at least partially doped of a second conductivity type opposite to the first conductivity type and extending in the substrate from said surface between at least some of the three-dimensional semiconductor elements such that, for each three-dimensional semiconductor element, a portion of the substrate of the first conductivity type extends all the way to said surface in contact with the three-dimensional semiconductor element or with the seed pad on which the three-dimensional element rests; characterized in that the device comprises: an at least partially reflective layer covering the semiconductor regions between the three-dimensional semiconductor elements to avoid the semiconductor regions to receive a light radiation through the surface; an insulating layer interposed between the semiconductor regions and said at least partially reflective layer; and electrically-insulating regions extending along the lateral edges of at least some semiconductor regions . an at least partially reflective layer covering the semiconductor regions between the three-dimensional semiconductor elements to avoid the semiconductor regions to receive a light radiation through the surface; an insulating layer interposed between the semiconductor regions and said at least partially reflective layer; and electrically-insulating regions extending along the lateral edges of at least some semiconductor regions . <EOS>