Hot-pressed chromium doped zinc sulfide infrared transparent ceramics

Abstract

The present study, for the first time, reports the successful consolidation of chromium doped zinc sulfide (ZnS) polycrystalline infrared (IR) transparent ceramics (maximum transmittance of 67% at 11.6 μm) via hot pressing under vacuum. The phase composition of the as-sintered Cr 2+ :ZnS ceramics was determined to be primarily cubic ZnS sphalerite, with a minor amount of hexagonal ZnS wurtzite. Scanning electron microscopy (SEM) observation of the sintered ceramics showed a highly consolidated microstructure. IR absorption and photoluminescence measurements revealed that the Cr 2+ ions are tetrahedrally coordinated within the ZnS host lattice. ZnSAs an extensively characterized II-VI wide bandgap semiconductor, zinc sulfide has been of significant interest for a long time due to its promising applications in various fields, including optical ceramics, phosphors, quantum dots, photocatalysts, and sensors [1][2][3][4]. When doped with transition metals and rare earth elements, ZnS can exhibit a wide range of luminescence behaviors in the visible and infrared regions [5][6][7][8][9]. In addition, due its exceptional performance as a material for room-temperature tunable solid state laser gain media in the mid-IR region, transition metal doped ZnS has inspired a tremendous amount of interest for researchers in past decades.In 1996, researchers at Lawrence Livermore National Laboratory demonstrated the potential of divalent transition metal doped zinc chalcogenides as materials for mid-IR laser applications © 2016. This manuscript version is made available under the Elsevier user license http://www.elsevier.com/open-access/userlicense/1.0/ [10]. Various divalent transition metals (Co 2+ , Ni 2+ , Fe 2+ and Cr 2+ ) were doped into ZnS/ZnSe/ZnTe hosts, and their room temperature mid-IR lasing performances were examined. It was determined that the tetrahedral substitution sites, rather than the octahedral sites, are more favorable doping sites for transition metals in the zinc chalcogenides. The tetrahedral coordination of dopants might contribute to the observed intense low-energy transitions, due to small crystal field splitting. Among the Zn chalcogenides, Cr 2+ doped ZnS/ZnSe showed exceptionally strong room-temperature absorption and emission in the mid-IR region. In addition, temperature-dependent lifetime measurements indicated that these materials revealed high (close to 80 and 100% for Cr:ZnS and Cr:ZnSe, respectively) luminescence quantum yield at room

Sintering behavior of calcium lanthanum sulfide ceramics in field‐assisted consolidation

“…It is observed that the CLS sample sintered at 1000°C has the best optical performance, with a maximum transmittance of 48.1% at 9.2 μm, which is ascribed to higher densification and lower porosity than the other two samples, as shown in Figure . Based on a comparison of spectra from sample measurement and measurement of the ambient atmosphere, it is determined that the absorption peaks in the 3.2‐4.2 μm range are due to atmospheric absorptions, with the absorption band at 3.2 μm attributed to water, and the peak at 4.2 μm due to CO 2 . The absorption peaks at 6.7 μm and 7.1 μm correspond to the C=O stretching modes in residual carbonates .…”

Synthesis of Fe:ZnSe nanopowders via the co‐precipitation method for processing transparent ceramics

“…Other reports detailed the use of wet chemical methods, which is a favorable technique for producing nanopowders with high sinterability, and these methods allow for atomic‐level mixing and dispersion of dopant ions. Li et al reported the synthesis of spherical and homogenous Cr:ZnS particles with a size of 100‐200 nm through a facile colloidal processing method, with the subsequent transparent ceramics exhibiting a maximum transmittance of 67% at 11.6 μm . Recently, ZnS and Fe:ZnS transparent ceramics were successfully prepared by the consolidation of nanopowders synthesized via co‐precipitation .…”

Mid‐infrared luminesce of ZnS:Cr2+‐glass composite and fiber

“…Mid‐IR light source is crucial for various applications related to spectroscopy, sensing, and imaging in the molecular fingerprint region . Design and fabrication of new luminescent materials operating in the Mid‐IR region lies in the core of this topic . In order to obtain materials with broadband emission, many approaches such as codoped with rare‐earth ions, embedding Mid‐IR activators into chalcogenide glasses, etc., have been explored .…”

“…[1][2][3][4][5][6][7][8] Design and fabrication of new luminescent materials operating in the Mid-IR region lies in the core of this topic. [9][10][11][12][13] In order to obtain materials with broadband emission, many approaches such as codoped with rare-earth ions, embedding Mid-IR activators into chalcogenide glasses, etc., have been explored. [14][15][16][17][18] Cr 2+ -doped II-VI semiconductors such as ZnS and ZnSe exhibit a unique blend of physical, spectroscopic, and optical parameters, which has been recognized as an excellent Mid-IR luminescent materials.…”