Rare Earth Centres in Mixed Compound Crystals

Abstract

A review of the Yb impurity related centres in mixed InP-based crystals has been presented. It is shown that Yb3+ ions can be utilized to probe alloy disorder, both in cationic (GaInP) and anionic (InΡΑs) alloys. The existence of alloy disorder manifested itself in the photoluminescence spectra reffecting local atomic structure of the Yb centres. The dominant emissions have been ascribed to the Yb-Ρ4 Ga1 2 and Yb-P4-Ga11In complexes in GaInP and to Yb-P4 and Yb-P 3 As centres in InPAs. The excitation and relaxation mechanisms of the 4 f -shell of Yb3+ ions were also investigated. It was found that the temperature quenching of the Yb 3 + luminescence was accompanied with the appearance of two thermally activated photoluminescence bands. It is suggested that photoluminescence at an energy of 25 meV below the energy gap is due to recombination of excitons bound at Yb-related centres. Relaxation of the excited 4 f-shell of Yb3+ ions proceeds via back transfer of the excitation energy from the 4f-shell to excitons bound at Yb-centres.

Effect of Layer Thickness on I-V Characteristics of GaInP Nanofibers Fabricated by Electrospinning on n-Si Substrates

“…Because of this, they exhibit some merits due to the defect centers, which cause a decrease of the conductivity [10,14,15]. GaInP/Si junctions are good candidates for tunneling junctions in multijunction cells and LEDs [10][11][12][13][14][15][16].…”