TY  - JOUR
AU  - Zou, Wei
AU  - Lou, Bibo
AU  - Kurboniyon, Mekhrdod S.
AU  - Buryi, Maksym
AU  - Rahimi, Farhod
AU  - Srivastava, Alok M.
AU  - Brik, Mikhail G.
AU  - Wang, Jing
AU  - Ma, Chonggeng
PY  - 2024
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/13187
AB  - In this study, we conducted an extensive investigation into broadband near-infrared luminescence of Cr3+-doped Ca3Y2Ge3O12 garnet, employing first-principles calculations within the density functional theory framework. Our initial focus involved determining the site occupancy of Cr3+ activator ions, which revealed a pronounced preference for the Y3+ sites over the Ca2+ and Ge4+ sites, as evidenced by the formation energy calculations. Subsequently, the geometric structures of the excited states 2E and 4T2, along with their optical transition energies relative to the ground state 4A2 in Ca3Y2Ge3O12:Cr3+, were successfully modeled using the ΔSCF method. Calculation convergence challenges were effectively addressed through the proposed fractional particle occupancy schemes. The constructed host-referred binding energy diagram provided a clear description of the luminescence kinetics process in the garnet, which explained the high quantum efficiency of emission. Furthermore, the accurate prediction of thermal excitation energy yielded insights into the thermal stability of the compound, as illustrated in the calculated configuration coordinate diagram. More importantly, all calculated data were consistently aligned with the experimental results. This research not only advances our understanding of the intricate interplay between geometric and electronic structures, optical properties, and thermal behavior in Cr3+-doped garnets but also lays the groundwork for future breakthroughs in the high-throughput design and optimization of luminescent performance and thermal stability in Cr3+-doped phosphors.
T2  - Materials
T1  - Unraveling Broadband Near-Infrared Luminescence in Cr3+-Doped Ca3Y2Ge3O12 Garnets: Insights from First-Principles Analysis
VL  - 17
IS  - 7
SP  - 1709
DO  - 10.3390/ma17071709
ER  - 

@article{
author = "Zou, Wei and Lou, Bibo and Kurboniyon, Mekhrdod S. and Buryi, Maksym and Rahimi, Farhod and Srivastava, Alok M. and Brik, Mikhail G. and Wang, Jing and Ma, Chonggeng",
year = "2024",
abstract = "In this study, we conducted an extensive investigation into broadband near-infrared luminescence of Cr3+-doped Ca3Y2Ge3O12 garnet, employing first-principles calculations within the density functional theory framework. Our initial focus involved determining the site occupancy of Cr3+ activator ions, which revealed a pronounced preference for the Y3+ sites over the Ca2+ and Ge4+ sites, as evidenced by the formation energy calculations. Subsequently, the geometric structures of the excited states 2E and 4T2, along with their optical transition energies relative to the ground state 4A2 in Ca3Y2Ge3O12:Cr3+, were successfully modeled using the ΔSCF method. Calculation convergence challenges were effectively addressed through the proposed fractional particle occupancy schemes. The constructed host-referred binding energy diagram provided a clear description of the luminescence kinetics process in the garnet, which explained the high quantum efficiency of emission. Furthermore, the accurate prediction of thermal excitation energy yielded insights into the thermal stability of the compound, as illustrated in the calculated configuration coordinate diagram. More importantly, all calculated data were consistently aligned with the experimental results. This research not only advances our understanding of the intricate interplay between geometric and electronic structures, optical properties, and thermal behavior in Cr3+-doped garnets but also lays the groundwork for future breakthroughs in the high-throughput design and optimization of luminescent performance and thermal stability in Cr3+-doped phosphors.",
journal = "Materials",
title = "Unraveling Broadband Near-Infrared Luminescence in Cr3+-Doped Ca3Y2Ge3O12 Garnets: Insights from First-Principles Analysis",
volume = "17",
number = "7",
pages = "1709",
doi = "10.3390/ma17071709"
}

Zou, W., Lou, B., Kurboniyon, M. S., Buryi, M., Rahimi, F., Srivastava, A. M., Brik, M. G., Wang, J.,& Ma, C.. (2024). Unraveling Broadband Near-Infrared Luminescence in Cr3+-Doped Ca3Y2Ge3O12 Garnets: Insights from First-Principles Analysis. in Materials, 17(7), 1709.
https://doi.org/10.3390/ma17071709

Zou W, Lou B, Kurboniyon MS, Buryi M, Rahimi F, Srivastava AM, Brik MG, Wang J, Ma C. Unraveling Broadband Near-Infrared Luminescence in Cr3+-Doped Ca3Y2Ge3O12 Garnets: Insights from First-Principles Analysis. in Materials. 2024;17(7):1709.
doi:10.3390/ma17071709 .

Zou, Wei, Lou, Bibo, Kurboniyon, Mekhrdod S., Buryi, Maksym, Rahimi, Farhod, Srivastava, Alok M., Brik, Mikhail G., Wang, Jing, Ma, Chonggeng, "Unraveling Broadband Near-Infrared Luminescence in Cr3+-Doped Ca3Y2Ge3O12 Garnets: Insights from First-Principles Analysis" in Materials, 17, no. 7 (2024):1709,
https://doi.org/10.3390/ma17071709 . .

TY  - JOUR
AU  - Umar, Zafari
AU  - Kurboniyon, Mekhrdod S.
AU  - Khyzhun, Oleg
AU  - Yamamoto, Tomoyuki
AU  - Ma, Chong-Geng
AU  - Brik, Mikhail G.
AU  - Piasecki, Michal
PY  - 2024
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11826
AB  - We report on the results of the first principles calculations based on density functional theory (DFT) of the electronic structure and mechanical properties of K2LiAlF6, both non-doped and doped with Cr3+ ions. The densities of states of K2LiAlF6 and the K2LiAlF6:Cr3+ phosphor as well as the crystal-field strength 10Dq, the Cr3+ 2E→4A2 emission energy, elastic constants, bulk and shear moduli, sound velocities and Debye temperature as functions of hydrostatic pressure ranging from 0 up to 40 GPa were calculated. The present DFT calculations indicate that, the band gap of non-doped K2LiAlF6 increases quadratically with increasing pressure. Further, the crystal field strength 10Dq and the 2E→4A2 emission energy, the Debye temperature, sound velocities and shear moduli of Cr-doped K2LiAlF6 increase with increasing pressure, while the 2E→4A2 emission energy becomes red-shifted, which indicates potential applicability of the studied system for pressure sensing. Such calculations for the title system were performed for the first time; the obtained results provide a firm basis for a deeper understanding of physical properties of both neat and doped functional materials.
T2  - Journal of Luminescence
T1  - First-principles calculations of the electronic structure and mechanical properties of non-doped and Cr3+-Doped K2LiAlF6 under pressure
VL  - 266
SP  - 120278
DO  - 10.1016/j.jlumin.2023.120278
ER  - 

@article{
author = "Umar, Zafari and Kurboniyon, Mekhrdod S. and Khyzhun, Oleg and Yamamoto, Tomoyuki and Ma, Chong-Geng and Brik, Mikhail G. and Piasecki, Michal",
year = "2024",
abstract = "We report on the results of the first principles calculations based on density functional theory (DFT) of the electronic structure and mechanical properties of K2LiAlF6, both non-doped and doped with Cr3+ ions. The densities of states of K2LiAlF6 and the K2LiAlF6:Cr3+ phosphor as well as the crystal-field strength 10Dq, the Cr3+ 2E→4A2 emission energy, elastic constants, bulk and shear moduli, sound velocities and Debye temperature as functions of hydrostatic pressure ranging from 0 up to 40 GPa were calculated. The present DFT calculations indicate that, the band gap of non-doped K2LiAlF6 increases quadratically with increasing pressure. Further, the crystal field strength 10Dq and the 2E→4A2 emission energy, the Debye temperature, sound velocities and shear moduli of Cr-doped K2LiAlF6 increase with increasing pressure, while the 2E→4A2 emission energy becomes red-shifted, which indicates potential applicability of the studied system for pressure sensing. Such calculations for the title system were performed for the first time; the obtained results provide a firm basis for a deeper understanding of physical properties of both neat and doped functional materials.",
journal = "Journal of Luminescence",
title = "First-principles calculations of the electronic structure and mechanical properties of non-doped and Cr3+-Doped K2LiAlF6 under pressure",
volume = "266",
pages = "120278",
doi = "10.1016/j.jlumin.2023.120278"
}

Umar, Z., Kurboniyon, M. S., Khyzhun, O., Yamamoto, T., Ma, C., Brik, M. G.,& Piasecki, M.. (2024). First-principles calculations of the electronic structure and mechanical properties of non-doped and Cr3+-Doped K2LiAlF6 under pressure. in Journal of Luminescence, 266, 120278.
https://doi.org/10.1016/j.jlumin.2023.120278

Umar Z, Kurboniyon MS, Khyzhun O, Yamamoto T, Ma C, Brik MG, Piasecki M. First-principles calculations of the electronic structure and mechanical properties of non-doped and Cr3+-Doped K2LiAlF6 under pressure. in Journal of Luminescence. 2024;266:120278.
doi:10.1016/j.jlumin.2023.120278 .

Umar, Zafari, Kurboniyon, Mekhrdod S., Khyzhun, Oleg, Yamamoto, Tomoyuki, Ma, Chong-Geng, Brik, Mikhail G., Piasecki, Michal, "First-principles calculations of the electronic structure and mechanical properties of non-doped and Cr3+-Doped K2LiAlF6 under pressure" in Journal of Luminescence, 266 (2024):120278,
https://doi.org/10.1016/j.jlumin.2023.120278 . .