Abstract: An LED comprises a semiconductor region including an active layer for generating light. An anode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. A reflective metal layer is bonded to the other major surface of the light-generating semiconductor region via an ohmic contact layer. Sufficiently thin to permit the passage of light therethrough, the ohmic contact layer is formed in an open-worked pattern to leave exposed part of the second major surface of the semiconductor region. A transparent, open-worked anti-alloying layer is interposed between the light-generating semiconductor region and the reflective metal layer, covering that part of the second major surface of the light-generating semiconductor region which is left exposed by the ohmic contact layer. The anti-alloying layer prevents the light-generating semiconductor region and reflective metal layer from alloying during heat treatments conducted in the curse of LED manufacture.

Abstract: An LED includes a semiconductor region having an active layer sandwiched between two confining layers of opposite conductivity types for generating heat. A cathode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. Attached to the other major surface of the semiconductor region, via an ohmic contact layer, is a reflective metal layer for reflecting the light that has traversed the ohmic contact layer, back toward the semiconductor region. A transparent antidiffusion layer is interposed between the ohmic contact layer and the reflective layer in order to prevent the ohmic contact layer and the reflective layer from thermally diffusing from one into the other to the impairment of the reflectivity of the reflective layer.

Abstract: A light-emitting diode having a silicon substrate on which there are successively formed a buffer layer, a p-type nitride semiconductor layer, an active layer, an n-type nitride semiconductor layer, and a current spreading layer. The current spreading layer is a lamination of a first and a second sublayer arranged alternately a required number of times. Composed of different compound semiconductors, the alternating sublayers of the current spreading layer create heterojunctions for offering the two-dimensional gas effect. The current spreading layer is so low in resistivity in a direction parallel to its major surface from which light is emitted, that the current is favorably spread therein for improved efficiency of light emission. A front electrode in the form of a metal pad is mounted centrally on the major surface of the current spreading layer in ohmic contact therewith.