Wydział Chemii

Joanna Jedoń

Agata Lazarowska

Tadeusz Leśniewski

Sebastian Mahlik

Mikhail G. Brik

Michał Piasecki

A. M. Srivastava

W. W. Beers

Eugeniusz Zych

2023

Journal of Alloys and Compounds

930

167435/1-167435/12

10.1016/j.jallcom.2022.167435

Naukowa

Angielski

Artykuł

We show the opportunity for tuning of the spectral position of the Mn⁴⁺ red emission in the series of double perovskites, Ba₂LaNbO₆:Mn⁴⁺, Ba₂La(Nb_0.8,Zr_0.1,W_0.1)O₆:Mn⁴⁺, and Ba₂La(Zr_0.5,W_0.5)O₆:Mn⁴⁺ with increasing chemically induced symmetry disturbance. Such a disorder appeared attractive to engineering phosphors for pressure sensors or horticultural applications, for instance. The goal of the present research, not yet systematically addressed in the literature, was to unveil the correlation between chemically induced controlled crystal lattice distortion and the luminescence of Mn⁴⁺. For this purpose, the luminescence of these phosphors was methodically investigated at different pressures and temperatures. A pressure-induced redshift of photoluminescent lines with the rate of − 4 cm⁻¹/kbar was found within the 0–230 kbar range, and the emission peak moved from 685 to 740 nm then. Furthermore, the cationic disorder allowed tuning of the Mn⁴⁺ luminescence making it useful for horticultural applications with a better fit between the emission wavelength and the strong chlorophyll absorption in the deep red part of the spectrum. The Mn⁴⁺ energy levels were computationally determined using the exchange charge model of the crystal-field theory which allowed for a deeper understanding of the experimental results. We found a correlation between the introduced disorder of the cationic subsystem and the energy of the Mn⁴⁺ emitting ²E_g level (R-line) as well as its intensity. This research brought a deeper understanding of the Mn⁴⁺-activated phosphors and, in turn, provides tips for a prudent search of materials for advanced practical uses.

Optical materials, Order-disorder effects, High-pressure, Luminescence, Oxide materials

CC-BY-NC-ND

http://dx.doi.org/10.1016/j.jallcom.2022.167435

http://www.elsevier.com