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Last Update
24.08.2016

Studies of undoped and rare earth (RE) doped zirconia (ZrO2) nanocrystals have shown that this material can be used for development of original optical sensor for oxygen detection in gasses. Multifunctional properties of the material allow to detect temperature and oxygen content during one cycle of the sensor operation. Temperature can be determined by analysing luminescence decay kinetics, while the oxygen content can be detected from luminescence intensity when compared to calibration data. Control of the sensor optical system is possible thanks to RE ion luminescence dependence on excitation, and the luminescence intensity depends on the oxygen content under excitation within charge transfer band. However, the RE luminescence intensity can be oxygen content independent in the case of direct RE excitation in a specific RE absorption line. Thus, a sensor made of RE doped zirconia would detect oxygen content and temperature of the surrounding gasses, and it is also possible to control its optical system stability. The sensor described above is protected by a patent from Poland and three International patents. The research was carried out in collaboration with scientists from Poland.

Up-conversion luminescence has been observed in RE doped zirconia nanocrystals, and it was found that the intensity of luminescence can be enhanced significantly by changing the way of charge compensation. It was proposed that the material can be potentially used as a marker for biologic objects at cell level. Further study might lead to development of a nanosized sensor for temperature control at single cell level.

Study of TlBr and radiation detectors made of this material showed that suitability of TlBr single crystals (quality of single crystals) for developing radiation detectors can be tested rapidly by using optical methods with fundamental absorption edge position determination and luminescence time-resolved spectroscopy.

The Cadmium-Zinc-Telluride is a well known material used in radiation detectors, and studies have shown that luminescence characteristics of this material differ depending on the source it was obtained from. It was also found that crystals with fast donor-acceptor luminescence are poorly suitable for radiation detectors. This is because the fraction of charge carriers generated by radiation interacts with donors and acceptors and thus cannot contribute to the electric signal of detector. Detector stimulation by infrared light enhances the electric output signal and improves energy resolution of the detector which can be explained by charges released from traps under infrared light stimulation.

ZnO is prospective material for different potential applications such as development of extra fast scintillators, new generation lighting sources, transparent conductive layers and new laser materials. Studies of luminescence and induced transient absorption of ZnO single crystals, nanocrystals and ceramics provide new knowledge about fundamental processes in these materials.

Due to the potential applications of optical transparent ceramics (e.g., YAG ceramics and others) the Laboratory of Solid State Radiation Physics have started studies on the optical properties of transparent ceramics focusing on nanostructured ceramics and the prospective material range, and it is planned to expand the scope of this research in future.

The up-conversion luminescence was detected and studied in fluorapatite (FAp) nanopowders and ceramics doped with RE ions.

The ZnO coatings on Zn were prepared by PEO methods and it is shown the effect of oxygen ions contents in atmosphere. The PEO method was developed for the different photonic applications.

The TSL methods was used for dosimetric materials, method shows the activation energies and spectra of studied materials.