The up-conversion luminescence of Zn1−xMgxS:Mn 2+ nanoparticles fabricated by an inorganic precipitation method is studied by using a near-infrared femtosecond laser. The up-converted luminescence is blueshifted when increasing the Mg composition because of weaker crystal field effect. Comparing with thin films, the luminescence of Zn1−xMgxS:Mn 2+ nanoparticles shifts several nanometers to the ...

By combining a high frequency modulation system for measurement of fluorescence with a phosphoroscope type apparatus for measurement of luminescence, recordings of fluorescence and luminescence induction kinetics under identical conditions were obtained. Both measuring sys­ tems tolerated the application of saturating pulses of white light for rapid, transient elimination of photochemical quenc...

Thiol-capped CdTe nanocrystals with cubic zinc blende structure are synthesized in aqueous solution. Their steady-state and time-resolved luminescence characteristics are studied at room and liquid nitrogen temperatures. A strong exciton luminescence peak at 2.3 eV dominates the emission spectrum of CdTe nanocrystals at room temperature, whereas the trap band centered at 2.0 eV undergoes substa...

Optical properties of Er doped Si=SiO2 superlattices and SiO=SiO2 superlattices are compared. In the case of Si=SiO2 superlattices with Si layers thicknesses between 2 and 19 nm polycrystalline like Si layers are observed after annealing. The samples show a very weak defect related red room temperature luminescence. No significant enhancement of the Er luminescence could be shown. The SiO=SiO2 ...

the mixed metal nanocomposite mgo∙al2o3∙zno has been prepared by coprecipitation method. the product was characterized by xrd. the average particle size was found to be 34.89 nm from xrd data. sem and sem-eds were studied for evaluating surface morphology and elemental composition. the ftir spectrum of prepared mixed metal nanocomposites mgo∙al2o3∙zno and mgo∙al2o3∙zno-curcumin were studied. th...

A series of solid-state luminescent dyes based on 2-phenylimidazo[1,2-a]pyridine (PIP) displaying a wide range of emitting colors from blue to red have been developed. Whereas 20-methoxy PIP (20MeOPIP, 10) shows blue luminescence, 20-hydroxy PIP (HPIP, 1) exhibits emission with large Stokes shift at around 500 nm that is known as the excited-state intramolecular proton transfer (ESIPT) luminesc...

Usually, the Kohlrausch (stretched exponential) function is employed to fit the luminescence decays. In this work we propose to use the Tsallis distribution as an alternative to describe them. We show that the curves of the luminescence decay obtained from the Tsallis distribution are close to those ones obtained from the stretched exponential. Further, we show that our result can fit well the ...

Although luminous bacteria are among the most accessible of light-producing organisms, until recently attempts to obtain the light-producing reaction in vitro have been unsuccessful. Owing partly to the development of ultrasensitive light-detecting apparatus such as the quantum counter (l), it has been possible in our laboratory to develop procedures required to obtain a sustained bright lumine...