Linear tunable NIR emission via selective doping of Ni2+ ion into ZnX2O4 (X=Al, Ga, Cr) spinel matrix

Structural Rigidity Control toward Cr3+-Based Broadband Near-Infrared Luminescence with Enhanced Thermal Stability

“…Al 3+ /Mn 2+ disorder and Mn 2+ –Mn 2+ aggregation in spinel Mg 1– x Al 2 O 4 : x Mn 2+ could enable a broadband NIR emission peaking at 825 nm . Ni 2+ and low-valent Bi ions activated glass materials also exhibit an attractive ultra-broadband NIR emission in the range of 800–1700 nm. , However, the NIR emission of Eu 2+ can be hardly shifted to the longer wavelength region by current methods, and the NIR luminescence efficiency of Mn 2+ , Ni 2+ , and Bi emission centers is still disappointing, so that the development of target NIR phosphors is still a challenge.…”

Interstitial Li+ Occupancy Enabling Radiative/Nonradiative Transition Control toward Highly Efficient Cr3+-Based Near-Infrared Luminescence

“…Broadband NIR emission can be observed via Eu 2+ , Mn 2+ , or Ni 2+ doping, which was only obtained in some limited structures. − Therefore, the current attention is mainly focused on Cr 3+ -activated NIR phosphors. Some of the high-efficiency (internal quantum efficiency (IQE) > 85%) Cr 3+ -doped NIR emission phosphors for LEDs have been developed, such as Ca 3 Sc 2 Si 3 O 12 :Cr 3+ (IQE = 92.3%), Gd 3 Sc 2 Ga 3 O 12 :Cr 3+ (IQE = 98.6%), Ga 2– x Sc x O 3 :Cr 3+ (99%), GaTaO 4 :Cr 3+ (IQE = 91%), etc. In particular, when the phosphor Gd 3 Sc 2 Ga 3 O 12 :Cr 3+ was used in an NIR pc-LED, a maximal NIR output power of 750 mW has been realized.…”

Modulation of Thermally Stable Photoluminescence in Cr3+-Based Near-Infrared Phosphors

“…CaO:Eu 2+ NIR phosphor (∼740 nm) with a record high external quantum efficiency (EQE) of 54.7% has been reported recently . NIR emissions of Mn 2+ and Fe 3+ ions have been also reported in different systems, such as MgAl 2 O 4 :Mn 2+ (∼825 nm), Li 5 Zn 8 Al 5 Ge 9 O 36 :Mn 2+ (∼800 nm), Mg 2 GeO 4 : Mn 2+ (∼735 nm), SrAl 12 O 19 :Fe 3+ (∼810 nm), and LiGaO 2 :Fe 3+ (∼748 nm). − Ni 2+ and Bi ion-activated glass materials exhibit ultrabroadband optical radiation in 800–1700 nm. , Among these abundant activators, the NIR emission of Eu 2+ ions hardly shifted to the longer wavelength region (after 800 nm) until now, and the NIR luminescence efficiency of Mn 2+ , Fe 3+ , Ni 2+ , and Bi 3+ ions is unsatisfactory . On the contrary, Cr 3+ ions have drawn much attention for their spin-allowed 4 T 2 → 4 A 2 transition, and they can be excited by the most effcient commercial InGaN blue chips.…”

“…21−25 Ni 2+ and Bi ion-activated glass materials exhibit ultrabroadband optical radiation in 800−1700 nm. 26,27 Among these abundant activators, the NIR emission of Eu 2+ ions hardly shifted to the longer wavelength region (after 800 nm) until now, and the NIR luminescence efficiency of Mn 2+ , Fe 3+ , Ni 2+ , and Bi 3+ ions is unsatisfactory. 28 On the contrary, Cr 3+ ions have drawn much attention for their spinallowed 4 T 2 → 4 A 2 transition, and they can be excited by the most effcient commercial InGaN blue chips.…”