N A Timofeeva
G.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences, Russia
Title: Investigation of regularities of photoluminescence centers formation in Fe2+ doped CVD-ZnSe by the two-photon confocal microscopy method
Biography
Biography: N A Timofeeva
Abstract
ZnSe crystals doped by Fe2+ are used as an active medium of lasers operated in the 3.5-5 μm spectral range. The characteristics of the medium important for laser applications depend not only on the nature and concentration of the doping component, but to a great extent on the type of the intrinsic or impurity defects of material. Such defects are defined by the conditions of crystal growth and also by the subsequent high temperature treatment, employed for matrix doping by active impurities. In this work, the unique technique of doping was developed and CVD-ZnSe samples with different Fe2+ concentration profiles were manufactured. The effective concentration of Fe2+ ions was at the 1019 at/cm3 level. The two-photon confocal microscopy method was used for investigating the nature and character of changes in the distribution of band-to-band and defect-impurity photoluminescence (PL) centers directly in the bulk of Fe2+: ZnSe polycrystals. The two-photon excitation was realized by a laser operated in the 0.75-1 μm range at room temperature, the PL spectra were registered in the 425-725 nm range. As a result, the PL “volume” maps of Fe2+: ZnSe polycrystalline samples were recorded reaching a depth up to 1 mm with a step 25 μm and a size of plane area 1Ñ…1 mm. The investigation of the maps reveals the regularities of PL centers formation in the bulk and at grain boundaries in the polycrystalline CVD-ZnSe due to the concentration of Fe2+ ions. The work was supported by the RSF grant â„–15-13-10028.