Room temperature blue light emitting p-n diodes from Zn(S,Se)-based multiple quantum well structures

Blue (494 nm) light emitting quantum well diodes based on Zn(S,Se) p-n junctions are demonstrated at room temperature. P-type Zn(S,Se) is realized by using a nitrogen rf plasma cell. The light emitting diode is formed on homoepitaxial GaAs buffer layers by molecular beam epitaxy. The S fraction of the alloy is selected to provide a lattice match between the II-VI active region and the GaAs buffer; the result is an active region having a dislocation density below 105/cm−2. The letter discusses emission characteristics as well as the x-ray rocking curve and transmission electron microscopy characterization of the structures.