Ultra-broadband near infrared phosphor with wide spectral range and long peak wavelength achieved by double-site occupation

Screening of Broadband Near-Infrared Cr3+-Activated Phosphors Using Ce3+ as a Probe

“…Since the CFS for Cr 3+ in a phosphor host can only be calculated from the photoluminescence spectrum, it is thus a challenge to predict the spectral width of Cr 3+ -doped NIR phosphor without knowing the CFS. Empirically, a phosphor usually exhibits broadband emission if the host contains multiple crystal sites for the doped Cr 3+ . , For example, MgTa 2 O 6 :Cr 3+ , La 2 MgZrO 6 :Cr 3+ , and ScNbO 4 :Cr 3+ with dual sites show a large FWHM of 140, 210, and 217 nm, respectively. For phosphors with more than two sites for Cr 3+ , their emission bands are much broader.…”

Rational design for broad near-infrared emission from a two-sited Rb2LiAlF6:Cr3+ phosphor with high efficiency and thermal stability for spectroscopic applications

“…Generally, the longer emission wavelength is always associated with a weaker crystal field. 36 According to the averaged bond lengths of Al–F in the [AlF 6 ( i )] and [AlF 6 ( ii )] octahedra, when a Cr 3+ ion replaced the Al 3+ ion in the [AlF 6 ( ii )] octahedron, it resulted in a longer emission at 796 nm. Therefore, the two types of six-coordinated Al 3+ lattice sites in the RLAF crystalline structure, which were available occupation sites for the Cr 3+ activators, could be further verified by analysing the decay trends of the Cr 3+ ions at the different luminescent sites.…”

Broadband short-wave near-infrared-emitting phosphor MgNb2O6:Cr3+ for pc-LED applications

“…Short-wave near-infrared (NIR) lighting materials and related devices have been extensively investigated for several decades, whereas nowadays the development of novel broadband NIR light sources of about 700-2500 nm is still arousing considerably keen interest in many applications, such as biological imaging, night vision, food examination, quantitative composition analysis, indoor planting, etc. [1][2][3][4][5] Traditional NIR light sources such as halogen lamps and supercontinuum lasers feature shortcomings of bulkiness, energy-inefficiency, high heat generation and short service life. These drawbacks inherently limit their use to satisfying miniature NIR spectroscopy compatible with mobile phones and other portable devices.…”