A Comparative Study of Eu3+-Doped Sillenites: Bi12SiO20 (BSO) and Bi12GeO20 (BGO)

Marcin Kowalczyk; Marcin Kaczkan; Andrzej Majchrowski; Michał Malinowski

doi:10.3390/ma16041621

A Comparative Study of Eu³⁺-Doped Sillenites: Bi₁₂SiO₂₀ (BSO) and Bi₁₂GeO₂₀ (BGO)

Materials (Basel). 2023 Feb 15;16(4):1621. doi: 10.3390/ma16041621.

Authors

Marcin Kowalczyk¹, Marcin Kaczkan¹, Andrzej Majchrowski², Michał Malinowski¹

Affiliations

¹ Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland.
² Institute of Applied Physics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw, Poland.

Abstract

The spectroscopic properties of Eu³⁺-doped Bi₁₂SiO₂₀ (BSO) were investigated and compared with that of Eu³⁺-doped Bi₁₂GeO₂₀ (BGO). The emission properties and the absorption spectra have been measured at 10 K as well as at 300 K (room temperature). Luminescence was detected due to the direct excitation of the ⁵D₀ level of Eu³⁺, as well as through the excitation of the ⁵D₁ level. The Judd-Ofelt theoretical framework was used to compute the radiative lifetimes (τ) and the omega parameters (Ω_λ). The electric dipole transition probabilities, asymmetry ratios (R), along with the branching ratios (β) were also determined based on the obtained experimental data. The strongest detected luminescence belongs to the ⁵D₀ → ⁷F₀ transition observed at 578 nm, similar to the BGO sillenite. Reasons for the major presence of the ⁵D₀ → ⁷F₀ emission, theoretically forbidden by the Judd-Ofelt Theory, were investigated and compared with that of the BGO sillenite. Obtained results showed that the strong ⁵D₀ → ⁷F₀ line is also present in Eu:BSO, indicating that this is a feature of the entire sillenite family and not just Eu:BGO.

Keywords: Bi12GeO20; Bi12SiO20; Eu3+ luminescence; sillenites; spectroscopy.

Grants and funding

No external funding was provided for this research. The APC was funded by Warsaw University of Technology.