Near-Infrared Broadband ZnTa₂O₆:Cr³⁺ Phosphor for pc-LEDs and Its Application to Nondestructive Testing

Broadband near-infrared (NIR) phosphors are necessary materials for developing portable NIR light sources. Moreover, exploiting an NIR phosphor with a main peak located beyond a wavelength of 900 nm remains a challenge because this spectral range has great potential in biological nondestructive testing and solution testing. In this study, a range of Cr³⁺-doped ZnTa₂O₆ (ZTO) phosphors were completely synthesized by a solid-state method, which show broadband Cr³⁺ emission centered at 935 nm with a large full width at half maximum (FWHM) of 185 nm due to two distorted octahedral sites. A packaged phosphor-converted light-emitting diode (pc-LED) device is used to penetrate a 5-cm-thick chicken breast and identify diverse solutions based on differences in the measured transmission spectra. The results indicate broad application prospects in the field of biological tissue penetration and solution analysis.