Mn4+ and Cr3+ ions in red and deep red-emitting phosphors: Spectral analysis and Racah parameter determination

The luminescence properties of the Mn 4+ and Cr 3+ -activated fluoride and oxide phosphors have been discussed in detail. The Mn 4+ and Cr 3+ -activated fluoride and oxide phosphors can be classified into five types from an aspect of the different luminescence properties: F–Mn, F–Cr, O–Mn, O–Cr-A, and O–Cr–B. The representative phosphors considered here are: BaSiF 6 :Mn 4+ (type F–Mn), K 2 NaScF 6 :Cr 3+ (type F–Cr), Sr 2 MgGe 2 O 7 :Mn 4+ (type O–Mn), MgAl 2 O 4 :Cr 3+ (type O–Cr-A), and BaZrSi 3 O 9 :Cr 3+ (type O–Cr–B). The photoluminescence (PL) and PL excitation spectra are analyzed based on the Franck−Condon analysis model with considering the electron−lattice vibration interaction (Huang−Rhys factors). The Racah and crystal-field-related parameters of such phosphors are determined and plotted very well on the Tanabe−Sugano energy-level diagram curve. • A discussion is given on various Mn 4+ and Cr 3+ -activated phosphors. • Spectroscopic classification of Mn 4+ and Cr 3+ -activated phosphors into five groups. • A new method is presented for exactly analyzing PL and PLE spectra. • Accurate determination of Racah parameters and related energy parameters.