A light emitting device (10) comprises a body (11) comprising a substrate (12) of a p-type semiconductor material. The substrate has an upper surface (14) and having formed therein on one side of the upper surface and according to a bulk semi-conductor fabrication process utilizing lateral active area isolation techniques: a first n+-type island (16) to form a first junction (24) between the first island and the substrate; and a second n+-type island (18) spaced laterally from the first island (16). The substrate provides a laterally extending link (20) between the islands having an upper surface. The upper surface of the link, an upper surface of the island (16) and an upper surface of the island (18) collectively form a planar interface (21) between the body (11) and an isolation layer (19) of the device. The device comprises a terminal arrangement to apply a reverse bias to the first junction, to cause the device to emit light. The device is configured to facilitate the transmission of the emitted light.