Synthesis and upconversion properties of GdOBr:Er3+ phosphors

GdOBr:Er3+ phosphors were synthesized by a simple solid-state reaction method. Under 980 nm and (or) 785 nm laser excitation, GdOBr:Er3+ (1%) samples present strong green and red upconverted emissions. The upconversion mechanisms were studied in detail through laser power dependence and excited state absorption process is discussed as the possible upconversion mechanisms. More interesting, the bright green upconverted emission is visible to the naked eye for GdOBr:Er3+ (1%) samples even excited by 1 mW 980 nm laser. Such phenomenon indicates that GdOBr:Er3+ may be used as upconversion phosphors.