High‐Power Broadband NIR LEDs Enabled by Highly Efficient Blue‐to‐NIR Conversion
Endale T. Basore, Huajun Wu, Wenge Xiao, Guojun Zheng, Xiaofeng Liu, Jianrong Qiu
Abstract
Abstract Phosphor‐converted light‐emitting diodes (pc‐LEDs) with broadband near‐infrared (NIR) emission have emerged as compact light sources for portable NIR spectroscopy. However, the associated broadband NIR phosphors suffer from low quantum efficiency (QE) and severe thermal quenching. Here the realization of highly efficient (internal QE ≈ 90%) and nearly zero‐thermal‐quenching broad NIR emission in Cr 3+ and Yb 3+ codoped Gd 3 Sc 1.5 Al 0.5 Ga 3 O 12 (GSGG) via efficient energy transfer from Cr 3+ to Yb 3+ is reported, whereby a high‐performance NIR pc‐LED is obtained that can generate ultra‐broad‐band NIR emission covering the whole range of 700−1100 nm with high output power (50 mW at a current of 100 mA) and high photoelectric efficiency (24% at a current of 10 mA). The results not only demonstrate that Cr 3+ and Yb 3+ codoped GSGG has great potential for compact NIR light sources, but also indicate that the strategy of energy transfer can be exploited for developing new NIR phosphors with both high QE and thermal stability.