Multifunctional optical sensing applications of luminescent ions doped perovskite structured LaGaO3 phosphors in near-infrared spectroscopy

Near-infrared (NIR) phosphor have attracted great attention due to its promising applications in bioimaging, night vision, medical diagnosis and food safety. However, the development of NIR phosphors with excellent sensing properties still remains a challenge. In this study, NIR phosphor LaGaO3: Nd/Cr has been successfully synthesized. Excitation at 460 nm the phosphor can exhibit excellent temperature sensing performance with the maximum absolute sensitivity 0.6043% K−1. The NIR phosphor also displays distinguished anti-thermal quenching performance with the emission intensity at 573 K retaining 78.34% of that at room temperature. In addition, there is a linear fitting relationship between the luminescence intensity ratio and applying stress. More importantly, NIR phosphor-converted light-emitting diode (pc-LED) has been fabricated by combining LaGaO3: Nd/Cr phosphors with blue LED chips, which shows a NIR output power of 979 mW and a photoelectric conversion efficiency up to 7.79% at 280 mA. Utilizing the prepared NIR pc-LED as a light source, the distribution of blood vessels and bones in human palms can be clearly observed with the assistance of infrared camera. These results indicate that the produced NIR phosphors have a wide range of optical sensing applications.