Boosting Applications with High‐Performance Near‐Infrared Phosphor‐Converted Light‐Emitting Diodes
Ruiyang Li, Yongfu Liu, Jin Chen, Liangliang Zhang, Jiahua Zhang, Xiaojun Wang, Guoxin Chen, Jun Jiang
Abstract
Abstract Near‐infrared (NIR) phosphor‐converted (pc) light‐emitting diodes (LEDs) are gaining popularity as smart NIR spectroscopy light sources. However, the low wall‐plug efficiency (WPE) of NIR pc‐LEDs has limited their applications due to the comprehensive properties of external quantum efficiencies (EQEs) and thermal stability for NIR phosphors. In this study, a simple strategy is presented to achieve high‐performance NIR phosphors by breaking the d–d parity forbidden transitions of Cr 3+ in the garnet host by introducing asymmetric vibrations via lattice distortions. The achieved EQE is as high as 44% at room temperature and maintains >98% of the initial EQE at 150 °C, demonstrating excellent thermal stability. Notably, these NIR phosphors enable unprecedented NIR pc‐LEDs with a record WPE of 26% driven at 100 mA. Consequently, the application of NIR pc‐LEDs is expanded to new areas such as real‐time heart rate monitoring and fingerprint recognition.