EFFECT OF ANNEALING TEMPERATURE ON STRUCTURE AND LUMINESCENCE PROPERTIES OF Ga2O3:Cr3+ MATERIALS

Abstract

In this work, Far-red emitting Ga₂O₃:Cr³⁺ materials were synthesized by the heat diffusion method. The effects of temperature sintered to phase structure and luminescence properties of the phosphors were investigated by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and steady-state photoluminescence (PL). XRD showed that the crystallinity of β –Ga₂O₃:Cr³⁺ phosphor belongs to the Monoclinic with C2/m space group. Photoluminescence excitation (PLE) spectrum shows that obtained phosphor could strongly absorb with two broads at 380 ÷ 500 nm and 520 ÷ >610 nm. Broad photoluminescence (PL) excitation bands at ∼600 ÷ 850nm were observed whose intensity increased with the annealing temperature.  A far-red LED prototype is obtained by coating the optimum powder on a blue LED chip (450nm). These results showed that β –Ga₂O₃:Cr³⁺ phosphor has the potential to produce far-red LEDs lighting for plants.