Ing. Vítězslav Jarý, Ph.D.

In my scientific work I am mostly interested in research and development in the field of solid-state physics, more particularly in the investigation of optical properties of novel potentially interesting materials which can find usage in the scintillating detectors, phosphors for white LED technology or phosphors to be used in solid state lasers.

In the experiments I conduct especially methods of time-resolved luminescence spectroscopy, including the measurements of absorption spectra (190 – 3200 nm spectral range), radioluminescence spectra (200 – 1050 nm spectral range), photoluminescence excitation and photoluminescence emission spectra (190 – 1050 nm spectral range), both photoluminescence and radioluminescence decay kinetics (decay times from tens of ps up to hours) of various material forms.

These forms can include bulk single crystals grown by many different techniques, optical ceramics, microcrystalline powders, thin layers, nano-materials or combined hetero-structured materials. In the next step, I thoroughly analyze all the obtained results and process them into scientific publications in internationally recognized journals, patents, or future grant proposals.

Generally, one of the key topics is understanding the influence of the structure of the given material on its optical properties, understanding the influence of various defects and traps, and finally, understanding the emission mechanism of the given material with regard to the way of its preparation.

In our laboratories, we are equipped with different cryostats to measure mentioned optical properties in the 4 – 800 K temperature range. Furthermore, we also have setups available to measure time-resolved cathodoluminescence, scintillation light yield, energy resolution and corresponding non-proportionality of scintillation response using many different radioisotopes (⁵⁷Co, ¹³⁷Cs, ²⁴¹Am, ²³⁹Pu, ²²Na,….), and, as a world unique opportunity, scintillation decays with ultrafast time resolution down to tens of ps excited by pulsed X-ray (40 kV). Thanks to various national and international collaborations, indeed many different materials coming from various laboratories and companies are investigated in our group.

Particularly, I am working on novel scintillating materials based on Pr³⁺ and Ce³⁺ -doped sulfides (KLuS₂, Lu₂S₃ in the form of single crystals) or on InGaN/GaN multiple quantum wells heterostructures, and on potentially interesting white LED phosphors derived from Eu²⁺-doped YAG and Eu²⁺&Ce³⁺ doped (K;Na)LuS₂ ternary sulfides. Other materials under investigation to be mentioned are various band-gap engineered Ce³⁺-doped garnets, thin layers of inorganic CsPbX₃ perovskites, Na₂O-ZnO-SiO₂ and K₂O-ZnO-SiO₂ glass systems containing scintillating particles, ZnO-based nano-scintillators and many others.