MBE growth of widegap II-VI injection lasers and LEDs

The successful p-doping of ZnSe by substitutional nitrogen using a plasma cell incorporated into a molecular beam epitaxy chamber has led to the development of electroluminescent devices employing carrier injection at a p-n junction and in which the active region is based on (Zn,Cd) Se/Zn(S,Se) multiple quantum well structures. We report on the performance of p-n junction MQW diode lasers and LEDs which are grown on both p-type and n-type GaAs substrates, and where sulfur is, or is not incorporated. For all structures, efforts were made to minimize dislocations by lattice matching the active II-VI region to the GaAs substrate. Some designs have dislocation densities below 10⁵ cm^-2. In this work we have obtained pulsed high power, high quantum efficiency laser emission up to room temperature conditions, and continuous operation at liquid nitrogen temperatures. Efficient LED devices are described which operate in the blue (494 nm) at room temperature.