Super Broadband Emission Across NIR‐I and NIR‐II Under Blue Light Excitation of Cr³⁺, Ni²⁺ Co‐Doped Sr₂GaTaO₆ Phosphor Achieved by Two‐Site Occupation and Effective Energy Transfer

Abstract

Abstract The performance of the near‐infrared phosphor‐converted light‐emitting diodes (NIR pc‐LEDs) mainly depends on the NIR emitting phosphors used. Cr 3+ doped materials can be excited by blue light chips, but their emission is located in the NIR‐I region (650–1000 nm). Ni 2+ doped materials are mainly located in the NIR‐II region (1000–1700 nm), but they cannot be effectively excited by blue light chips. Herein, Cr 3+ , Ni 2+ mono‐doped, and co‐doped Sr 2 GaTaO 6 NIR emitting phosphors are prepared and investigated. Cr 3+ and Ni 2+ ions occupy two octahedral sites of Ga 3+ and Ta 5+ . The co‐doping of Cr 3+ ions has achieved two breakthroughs. One is to shift the optimal excitation wavelength from violet light to blue light due to the energy transfer (efficiency up to 70%) from Cr 3+ to Ni 2+ . The other is to achieve the broadband and continuous emission across NIR‐I and NIR‐II regions (650–1700 nm, with a full width at half maximum (FWHM) of 410 nm (173 nm + 237 nm)). The prepared Sr 2 GaTaO 6 : 0.02Cr 3+ , 0.01Ni 2+ phosphor is combined with a commercial 460 nm blue chip to realize its application in organic compounds identification, night vision, and biological imaging. This work points out a direction for the future development of efficient super broadband NIR‐emitting phosphors.