Near-Infrared Persistent Phosphor-Mediated Smart Sensing Light-Emitting Diodes for Advanced Driver Assistance Systems

Compared with conventional phosphor-converted near-infrared light-emitting diodes (NIR pc-LEDs), near-infrared persistent phosphor-converted LEDs (NIR ppc-LEDs) are applicable not only in conventional systems but also novel devices in the fields of intelligent security, driverless vehicle technology, and virtual reality. However, NIR ppc-LEDs have not been extensively investigated. Herein, a novel NIR ppc-LEDs with the prepared SrAl12O19: Fe3+, Mg2+, Ti4+ NIR persistent phosphors is designed. In relation to pc-LEDs, the new ppc-LED exhibits full-spectral responsive sensing ability during the photostimulated mediation of lattice defects. Furthermore, using the ppc-LED as a smart sensing LED in a digital NIR imaging system, optical feedback could be converted to a digital signal in a self-regulated visible-to-NIR operation mode. These results imply that the designed ppc-LED, as a smart sensing LED with full-spectral responsive ability, greatly enhances the sensitivity of digital NIR imaging, particularly low-light digital NIR imaging, which has recently drawn considerable attention in the fields of advanced driver assistance systems and VR/AR technology.