A facile approach towards fabrication and ultrabroad band emission properties of nickel ion-doped ZnAl2O4 transparent ceramics

Chen

Advanced Optical Materials

et al. 2023

Applications in near‐infrared (NIR) have been explored significantly in many fields, including bioimaging, night vision, plant growth, and chemical analysis. Different emission profiles are required within the same industry. Developing luminescent materials with different tuning methods is reliable for controlling the NIR regions (NIR‐I, 700–1000 nm; NIR‐II, 1000–1700 nm). Spinel phosphors are promising candidates due to their ability to modulate the crystal field. Understanding the parameters that influence the degree of inversion in spinel compounds is crucial to harness the variability of the spinel structure. Cr3+ and Ni2+ are ideal activators for NIR‐I and NIR‐II emissions, respectively. However, there is a need for phosphors that emit in the NIR‐II region when excited by visible light. Although the energy transfer method combining two activators is considered, this review focuses on different types of spinel structures, discussing their types and common strategies to tune the host structure. The goal is to achieve desired shift and broadness of the entire NIR spectrum, highlighting the importance of spectrum tuning for practical applications.

Section: Ni-dopedmentioning

confidence: 99%

Tunable Spinel Structure Phosphors: Dynamic Change in Near‐Infrared Windows and Their Applications

Chen

Advanced Optical Materials

et al. 2023

“…Transition metal ions can be as the candidate dopants to realize a broadband NIR luminescence, which have attracted considerable attention 10 . Among them, Ni 2+ ions give a broadband NIR emission centered at ∼1300 nm when they occupy the octahedral site in materials, such as Ni 2+ ‐doped ZnAl 2 O 4 nanostructures, 11,12 Ni 2+ ‐doped β‐Ga 2 O 3 nanocrystals, 13 Ni 2+ ‐doped yttrium aluminum gallium garnet phosphors, 14 and so on, which is owing to both its 3d 8 electronic configuration and intense influence on the splitting energy level caused by the electrostatic potential, because of the contribution of neighborhood ions. Researchers have made many attempts to improve the emission intensity of this fluorescent powder, such as increasing the excess or deficiency of Zn 2+ in the raw material, 15 doping Ge 4+ , Mg 2+ , or Li + with average charge, 16,17 and adjusting the crystal field by doping Al 3+ , Sn 4+ , or other elements to change the proportion of ions in the matrix 6,14,18 .…”

Section: Introductionmentioning

confidence: 99%

Incorporation of Eu³⁺ in ZnGa₂O₄:Ni²⁺ for improved NIR persistent luminescence located in second transparency window

Jin,

Zhang,

et al. 2023

J Am Ceram Soc.

It is well known that near‐infrared (NIR) persistent phosphors have rather low absorption coefficients of biological tissues for NIR light. However, recent research shows that the phosphors emitting NIR lights in second (NIR‐II, 1000–1350 nm) and third (NIR‐III, 1500–1800 nm) biological window have advantages over that in NIR‐I (650–900 nm). Although ZnGa2O4:Ni2+ outputs near‐infrared (NIR) emission and afterglow located in NIR‐II, the weak signal significant limits its application. In this work, persistent luminescent phosphors of ZnGa2O4:xNi2+, yEu3+ (x = 0–0.013, y = 0.01–0.06) (termed as ZEGN) were synthesized via a traditional high‐temperature solid‐state reaction, which feature a broad emission band in the second near‐infrared (NIR‐II) window. The phosphors exhibit a broad NIR emission at about 1300 nm after ultraviolet (UV) or orange‐red lights excitation, arising from the 3T2(3F)→3A2(3F) transition of Ni2+. However, incorporation of Eu3+ ions, the NIR emission intensity significantly increases with the increase of Ni2+ ion concentration, reaching the maximum by 18 times at x = 0.005. Removing the light source, the sample still outputs intense NIR afterglow and red afterglow that can last over 500 s. It is noteworthy that the red afterglow of Eu3+ shows a dramatically decrease but the NIR afterglow increases with increasing the Ni2+ ion concentration, because of energy transfer. Under the excitation of 282‐nm UV light, the ZGEN sample exhibits a good thermal stability. The phosphor offers a promising application in biological imaging due to broadband NIR‐II light and afterglow.This article is protected by copyright. All rights reserved

Journal of the European Ceramic Society

“…[35][36][37][38] However, most transparent oxide ceramics are generally prepared from raw nanopowders or/and cubic crystalline powders through different sintering techniques (vacuum sintering, spark plasma sintering, hot uniaxial sintering). [34,39,40] Numerous studies report transparent spinel ceramics such as MgAl 2 O 4 [33,41,42] or ZnAl 2 O 4 [43][44][45][46][47][48] while the zinc gallate spinel has not been yet achieved as a transparent ceramic. Indeed, the difference of evaporation speed of ZnO and Ga 2 O 3 (i.e.…”

Section: Introductionmentioning

confidence: 99%

First ZnGa2O4 transparent ceramics

Mével¹,

Carreaud²,

Delaizir³

et al. 2021

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