An LED comprising a light-generating
semiconductor region having an
active layer sandwiched between two confining
layers of opposite
conductivity types. A
cathode is arranged centrally on one of the opposite major surfaces of the
semiconductor region from which is emitted the light. An array of discrete gold regions are formed via
transition metal regions on the other major surface of the
semiconductor region at which is exposed one of the confining
layers which is of n-type AlGaInP semiconductor material. The gold is thermally diffused into the confining layer via the
transition metal regions at a temperature less than the eutectic point of gold and
gallium, thereby creating an array of
ohmic contact regions of alloyed or intermingled gold and
gallium, which are less absorptive of light than their conventional counterparts, to a thickness of 20 to 1000 angstroms. After removing the
transition metal regions and gold regions from the surface of the light-generating semiconductor region, a
reflective layer of aluminum is formed so as to cover both the
ohmic contact regions and the exposed surface portions of the AlGaInP confining layer. An electroconductive base-plate of doped
silicon is then bonded to the
reflective layer.