Tailoring the Cr3+ Emission via Combinatorial Management of Crystal-Field and Energy Transfer for Multiple NIR LEDs

Near-infrared (NIR) phosphors converted light-emitting diodes (NIR pc-LEDs) are ideal NIR sources for versatile applications, which imply the practical significance in tailoring the emission of the NIR phosphors to enhance the performance for specific application. Herein, a paradigm of tailoring the emissions in a series of Cr3+-doped phosphors to match the applications in NIR lighting, detection, and short-wave infrared sources through combinatorial management of crystal-field and energy transfer is presented. The emission band largely increases from 84 to 190 nm when the introduction of [MgO6]-[GeO4] into Y3Ga5O12:0.08Cr(3+) forms Y3MgxGa5-2xGexO12:0.08Cr(3+) through the substitution of [GaO6]-[GaO4]. Such a large increase in width makes it suitable for near-infrared lighting to near-infrared detection. Moreover, the Yb3+, Nd3+ and Er3+ are doped to construct energy transfer with Cr3+, broadening the emission infrared region and enhanced thermal stability. An optimized Yb3+ emission dominates Y3Ga5O12:0.4Cr(3+),Yb3+ phosphor has excellent thermal stability (129%@423 K) and is suitable for high-power short-wave infrared sources. The presented work not only provides a series of well-performed NIR phosphors, but only lights up the avenue for designing the Cr3+ emission for specific application.