DEGRADATION RELATED DEFECTS IN ALGAAS GAAS VISIBLE LASERS/

The defects resulting in degradation of AlGaAs/GaAs visible lasers hav e been studied in this paper by deep level transient spectroscopy (DLT S) and ultrasonic Abrahams-Buiocchi (AB) etching (USABE) or ultrasonic Doniach-Sunjic (DS) etching (USDSE). The dislocations and deep levels in AlGaAs/GaAs degrade the visible lasers seriously. The donor-relate d deep centers (DX centers), are non-irradiating traps and attached to the dislocations in n-type AlGaAs. While a laser is in light-emitting operation, most of the injected carriers focus on the dislocations in company with DX centers, which results in the degradation of the AlGa As/GaAs lasers. The effects of defects in AlGaAs/GaAs on relative lase rs can be avoided by growing an InGaAs buffer layer between the AlGaAs cladding layer and GaAs substrate.