Electroluminescent GaAs diodes have been shaped as truncated cones with thep‐njunction at the apex to direct a large fraction of the radiation toward the base of the cone within the critical angle for transmission. Devices having an efficiency at 77°K of 8% have been fabricated. Efficiency is defined here as the radiant power out the base per unit electrical power input. It is calculated that improved devices of this type will have efficiencies of about 18%.