POSSIBILITY OF ANALYZING THE TYPE OF IMPURITIES IN SEMICONDUCTORS BY APPLICATION OF BISTABILITY IN LUMINESCENCE

Besides the well-known phenomenon of bistability in transmission, the excitation of thin (5.5 mum) CdS films by the 514.5 nm Ar+-laser line generates all-optical bistability in luminescence in the near-infrared region of the spectrum. With the application of this feature, the det ermination of the type of impurities, donors or acceptors in GaAs is p ossible. The novel method proposed here underlies the principle that d ifferently contrasting bistable loops in luminescence are clearly obse rved if n-type, intrinsic or p-type GaAs wafers are used as cut-off fi lters for the bistable luminescent emission of thin CdS films.