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

Abstract

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.

Keywords

• advanced driver assistance systems
• digital near-infrared imaging
• Fe3+
• near-infrared persistent phosphor
• smart sensing light-emitting diodes