Ultra-broad NIR emission from two-site Cr3+ occupation in fluoride phosphor via composition-driven structural transformation

Composition–structure–luminescence and enhancement of Cr3+ activated broadband near infrared phosphors for night vision, bio-imaging, and noninvasive detection

“…5b), owing to the weaker electron–phonon coupling (EPC) effect and the decreased crystal-field strength. Usually, the EPC strength relates to the value of Huang–Rhys factor ( S ), which can be obtained with the help of the relationship between temperature and FWHM: 62,63 …”

Broadband short-wave infrared Mg4Nb2O9:Cr3+,Li+ phosphor for nondestructive safety detection and biomedical imaging

“…22 Nearly all Cr 3+ -activated (hexa)fluorides were reported to feature PL peaks in the range of 710–800 nm and a short band edge wavelength in the range of 950–1000 nm. 1,23–29 Alternatively, many Cr 3+ -doped multicomponent oxides, such as BaMgAl 10 O 17 , 30 LiIn 2 SbO 6 , 31 Y 2 CaAl 4 SiO 12 , 32 Mg 3 Ga 1.9 In 0.1 GeO 8 , 33 GdAl 3 (BO 3 ) 4 , 4 Ca 2 LuHf 2 Al 3 O 12 , 34 and LaMgGa 11 O 19 , 35 were carefully optimized via site engineering/cation (co-)substitution to possess high QE and broadband spanning from 700 to 1100 nm, while most of these still exhibit undesirable PL properties like peaks <850 nm (deficient in 850–1100 nm), limited full-width at half-maximum (FWHM), and low internal/external QE. Thus, the active and continuous exploration of simple component oxides for novel NIR Cr 3+ -activated phosphors is still challenging and urgently required for broadband NIR pc-LEDs as well as its miniature NIR spectroscopy applications.…”

“…the range of 950-1000 nm. 1,[23][24][25][26][27][28][29] Alternatively, many Cr 3+ -doped multicomponent oxides, such as BaMgAl…”

An efficient LiSrGaF6:Cr3+ fluoride phosphor with broadband NIR emission towards sunlight-like full-spectrum lighting

“…However, for fluoride phosphors, such far emission has not been achieved, which is mainly dependent on the choice of fluoride matrix (ScF 3 :Cr 3+ , λ em = 853 nm, the emission range is 700–1150 nm). 29 In our previous study, we successfully synthesized thermally stable LiBAlF 6 :Cr 3+ (B = Sr, Ca) NIR phosphors with ultra-band emission (FWHM = 155 nm). 10 The discovery of such types of fluoride phosphor with excellent NIR luminescence properties encourages us to continue to explore the novel material systems with similar crystal structures.…”