Search

Component modulation strategies are widely used to modulate the PL properties of fluorescent materials. Metal halide perovskites (MHPs) have many advantages for optical applications, one of which is the excellent structural tunability. In this work, a series of Cs2InCl5·H2O:xCr3+ phosphors were synthesized by a simple hydrothermal method, obtaining a broadband near-infrared (NIR) emission in the 800–1200 nm range with a peak at 910 nm under 360 nm excitation. Unlike the widely used B-site cation modulation, co doping Rb+/K+ at A sites improves the structural rigidity and thus enhances the emission intensity and luminescence thermal stability of the Cs2InCl5·H2O:Cr3+ phosphor. In particular, the emission intensity of (Cs0.7K0.3)2InCl5·H2O:0.25Cr3+ at 125 °C can retain 52% of that at room temperature. Due to its excellent performance, the (Cs0.7K0.3)2InCl5·H2O:0.25Cr3+ phosphor in combination with 380 nm ultraviolet chips shows potential applications in non-destructive testing and night vision. This strategy provides new ideas for the modulation of MHP-based fluorescent materials in the future. [ABSTRACT FROM AUTHOR]

Most near-infrared (NIR) phosphors suffer from short emission wavelength (<1000 nm) and narrow full width at half maximum (FWHM) values below 200 nm, restricting their broader applications in non-destructive tests, spectral analysis and photovoltaic fields. This study presents the successful synthesis of the wolframite-type compound InNbTiO6:Cr3+, with Cr3+ occupying a single In3+ site. Under green light irradiation, it emits an ultra-broadband NIR spectrum centered at 965 nm with a FWHM of 231 nm. Substituting In3+ with Ga3+ induces a blue shift in the emission peak from 969 nm to 934 nm, concomitant with an enhancement in the optical properties. To be specific, the NIR luminescence intensity of In0.58NbTiO6:0.02Cr3+,0.4Ga3+ is enhanced by a factor of 2.3, and its thermal stability is improved from 22.3%@400 K to 41.3%@400 K compared to In0.98NbTiO6:0.02Cr3+. The NIR pc-LED is fabricated by integrating the In0.58NbTiO6:0.02Cr3+,0.4Ga3+ phosphor with a 520 nm chip, showcasing its potential for multifunctional applications in solar cells, spectral analysis, and night vision technologies. [ABSTRACT FROM AUTHOR]