ZnSe-based heterostructures for blue-green lasers

We review the current status of research activity on ZnSe-based heterostruc tures for blue-green laser diodes (LDs), focusing on a few selected critica l issues. Early investigations on defect microstructures allowed to strongl y enhance the lifetime of LDs. However, the LD lifetime seems to saturate n ow, and we point out that the model proposed for explaining the degradation of LD does not predict such a saturation. Next, we detail the mechanisms r esponsible for carrier compensation in p-type ZnSe and we survey the proper ties of ZnMgSSe and ZnMgBeSe wide bandgap quaternary alloys which are used as cladding layers in LDs. We emphasize that the low p-type dopability of Z nSe and related materials has a dramatic impact on the performance of LDs i n terms of emitted wavelength as well as device lifetime. (C) 2000 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.