Transmission electron microscopic and optical spectroscopic studies of Ni²⁺/Yb³⁺/Er³⁺/Tm³⁺ doped dual‐phase glass‐ceramics

Abstract

Ni2+/Yb3+/Er3+/Tm3+ codoped transparent glass‐ceramics (GCs) containing both hexagonal β‐YF3 and spinel‐like γ‐Ga2O3 dual‐phase nanoparticles (NCs) are synthesized by melt‐quenching and subsequent heating procedures. Two techniques of transmission electron microscopy (TEM) nanoanalytics and optical spectroscopy are conjugated to understand the distribution of the rare‐earth ions (REs) and transition metals (TMs) in the nanostructured GCs. It is found that the REs are located predominantly in β‐YF3, whereas the TMs in γ‐Ga2O3 NCs. As a result, energy transfer (ET) between the REs and TMs is considerably suppressed due to the large spatial separation (> 3 nm), but it is enhanced between the REs partitioned in the β‐YF3 NCs. This has important implications for intended and demanding photoluminescence functions. For example, an ultrabroadband near‐infrared (NIR) emission in the wavelength region of 1000‐2000 nm covering the entire telecommunications window is observed for the first time. Meanwhile, intense upconversion (UC) emissions covering the 3 primary colors and locating in the first biological window can be also recorded under excitation by a single pump source at 980 nm.

Controlling Selective Doping and Energy Transfer between Transition Metal and Rare Earth Ions in Nanostructured Glassy Solids

“…The separation is much longer than the critical distance and thus prohibitive of any ET between RE ions and Ni 2+ . In the case where adverse CRs between TM and RE ions must be avoided, the dual‐phase GCs appear to be an excellent material of choice . The ET parameters determined for the single‐phase GC, including the ET efficiency, η ET = (1 − τ/τ 0 ) × 100, where τ and τ 0 are the lifetimes of the donor emission in the presence and absence of the acceptor, respectively, and the ET probability, W ET (S −1 ) = [η ET /(1 − η ET )]/τ 0 , are listed in Table .…”

Thermal and crystallization behavior of SiO2‐PbF2 glass system in the presence of ErF3 and Al2O3

“…F‐shell electron energy levels of Er 3+ protected with outer layers from around chemical environment. As a result, external factors had the least effect on the position of Er 3+ energy levels; therefore, these peaks appeared with same pattern and position in all samples regardless of their composition …”

“…Several decades have passed from introduction of upconversion phenomenon as an anti‐Stokes process and rare‐earth‐doped oxyfluoride glass‐ceramics in 1970s by Auzel . Upconversion materials have recently attracted great attentions due to their specific optical features in various fields such as telecommunication windows, biological applications, efficient photovoltaic solar cells, and high capacity data storage optical devices . Rare‐earth ions are the most utilitarian elements in these areas, and special characteristics of oxyfluoride glass‐ceramics make them the most interesting hosts for rare‐earth ions in optical applications.…”

Correlation between ultrabroadband near‐infrared emission and Yb3+/Ni2+ dopants distribution in highly transparent germanate glass‐ceramics containing zinc gallogermanate nanospinels

“…However, our recently studies provided clear evidence that RE ions accumulate preferentially in the embedded nanospinels (eg, γ‐Ga 2 O 3 ), and perhaps more interestingly the doping efficiency of RE ions in the nanospinels depends on the ionic radius of the RE ion dopants . The simultaneous partitioning of TM and RE ions in the embedded nanospinels imposes a strong influence on the ET processes occurring between the dopants, such that the PL functions can be tailored in demand …”