High-power NIR-II LED of Nd3+ doped glass ceramics towards portable imaging

Abstract

Near-infrared (NIR) sources exhibit unique photophysical properties, such as excellent signal-to-noise, high tissue penetration and so on, which stretches many prospective applications in biological imaging, night vision and other fields. However, the emission wavelength of NIR light-emitting diodes (LEDs) mostly locates in the range from 650 to 950 nm (NIR-I) where the heat accumulation cannot be overlooked, especially working at high-power, which limits the application scenarios. Here, Nd³⁺-doped LiGa₅O₈ glass ceramics (GCs) prepared by an in situ glass crystallization strategy show notable NIR-II emission. The fabricated glass ceramics-converted (GCs-converted) LED exhibits strong heat dissipation performance, and the surface temperature (39.2 °C) is much lower than the temperature (135.1 °C) of the phosphor-converted counterpart operated at high-power (10 W), which is attributed to the good thermal conductivity of GCs and the designed hollow structure of the LED device. Furthermore, the highly stable GCs-converted LED effectively avoids the yellowing on aging of the conventional organic adhesive. Accordingly, the portable high-power NIR LED has been proven to be an excellent candidate for multi-applications such as imaging, night vision, nondestructive analysis and so on. This work initiates the development of GCs with efficient NIR luminescence and opens up a new avenue for high-power NIR LEDs with GCs.