Cr3+ and Nd3+ co-activated garnet phosphor for NIR super broadband pc-LED application

Abstract

Near-infrared phosphor converted light emitting diodes (NIR pc-LEDs), as a compact light source, play a constructive role in wearable optical biosensing devices. In order to detect the properties of different substances, the NIR emission should be as wide as possible. The typical strategy for broadening the band is the superposition emission of Cr3+ and Yb3+, the bandwidth of which is 300–320 nm, and it needs to be further broadened. In this paper, NIR Ca2LuZr2Al3O12 garnet phosphor, co-activated by Cr3+ and Nd3+, is prepared. The emission quantum efficiencies of Nd3+ at 900 nm and 1060 nm are close to 100%, and the emission band is complementary to that of Yb3+ at 1030 nm. An efficient super broadband NIR pc-LEDs (47.6 mW@100 mA), with the bandwidth of 350 nm, are achieved. The bandwidth and the efficiency of the pc-LEDs are improved greatly, compared with other reported ones.