Unraveling Luminescent Energy Transfer Pathways: Futuristic Approach of Miniature Shortwave Infrared Light-Emitting Diode Design
Veeramani Rajendran, Kuan‐Chun Chen, Wen‐Tse Huang, Mikołaj Kamiński, Maciej Grzegorczyk, Sebastian Mahlik, Grzegorz Leniec, Kuang‐Mao Lu, Da‐Hua Wei, Ho Chang, Ru‐Shi Liu
Abstract
Phosphor-converted shortwave infrared phosphor light-emitting diodes (pc-SWIR LEDs, 900–1700 nm) are promising next-generation portable light sources for spectroscopy, security, optical communication, and medical applications. A typical design strategy involves energy transfer from Cr 3+ to Ni 2+, and thus, energy transfer from Cr 3+ –Cr 3+ pairs to Ni 2+ ions is important but challenging. Here, we report a Sr 1– x La x Al 5.92 Cr 0.08 Ga 6– x O 19: x Ni 2+ ( x = 0–0.09) series for the SWIR emissions range of 900–1600 nm due to an energy transfer from Cr 3+ and Cr 3+ –Cr 3+ pair to Ni 2+ . Short-range structural studies using electron paramagnetic resonance and magnetometry measurements reveal that Ni 2+ ions likely exist as isolated Ni 2+ ions and Cr 3+ –Ni 2+ pairs rather than forming Ni 2+ –Ni 2+ pairs. The fabricated prototype SWIR pc-LED delivers a radiant flux of 12.43 mW under a 350 mA driving current. This work provides insights into the codopant strategy for energy transfer and the design of promising next-generation SWIR phosphors.