Room temperature laser operation of wide band-gap II–VI laser diodes.

A lifetime of over 100 h has been achieved at room temperature under CW conditions for a ZnCdSe/ZnSSe/ZnMgSSe separate-confinement heterostructure laser diode with a dark-spot density lower than 3 × 103 cm−2. The density of pre-existing crystal defects such as stacking faults is reduced when there is a GaAs buffer layer on the GaAs substrate and Zn is irradiated before ZnSe growth. We have entered into a stage where the operation of II–VI laser diodes is limited by recombination enhanced defect reaction. Despite possible rapid degradation mechanisms, especially those related to II–VI materialsʹ higher ionicity than that of III–V materialʹs, II–VI laser diodes have shown a lifetime of more than 100 h for the first time.