Ultra-broadband near-infrared Gd3MgScGa2SiO12: Cr, Yb phosphors: Photoluminescence properties and LED applications

Abstract

Developing novel broadband near-infrared (NIR) phosphors is crucial to promote NIR phosphor-converted light emitting diodes (pc-LEDs) development. In this work, a new ultra-broadband NIR phosphor Gd 3 MgScGa 2 SiO 12 : Cr 3+ (GMSGS) was achieved by replacing Sc 3+ -Ga 3+ in Gd 3 Sc 2 Ga 3 O 12 with Mg 2+ -Si 4+ . Under the excitation of blue light, the peak emission wavelength of GMSGS: 0.04Cr 3+ is about 820 nm with a full width at half maximum (FWHM) of ∼180 nm and an internal quantum efficiency (IQE) of 50 %. Benefited from the superposition of Cr 3+ emission and highly efficient Yb 3+ emission excited by energy transfer (ET) from Cr 3+ , the codoped GMSGS: 0.04Cr 3+ , 0.007Yb 3+ phosphor shows an ultra-broadband of 300 nm. Moreover, Yb 3+ -codoping improves the thermal stability due to the ET from Cr 3+ to more thermally stable Yb 3+ emitters, and the integrated intensity of GMSGS: 0.04Cr 3+ , 0.007Yb 3+ at 400 K was 63 % of that at room temperature. The packaging results exhibit that ~20 mW output power was achieved at 100 mA input current, which suggests promising potential of GMSGS: Cr 3+ , Yb 3+ phosphor in NIR pc-LED applications. • A novel broadband NIR garnet phosphor Gd 3 MgScGa 2 SiO 12 :Cr 3+ is developed. • The phosphor shows broadband NIR emissions in 700–1100 nm (λ max = 820 nm). • The phosphor exhibits high quantum yield (~50 %) and good thermal stability. • An ultra-broadband GMSGS: Cr 3+ , Yb 3+ phosphor was achieved owing to the energy transfer from Cr 3+ to Yb 3+ . • The NIR phosphor-converted LED with the NIR output power with ~20 mW at 100 mA drive current is achieved.