Light Conversion by Size Control of Inorganic Phosphors
A unique method, so called, hydro-thermal synthetic method was applied to produce nano-sized inorganic blue (Y2SiO5:Ce) and red (Y2O2S:Eu+3) emitting phosphors. Electron microscopy revealed that the nano-sized emitting phosphor particles have spherical shape with 23-50nm in size. The particles can effectively change ultraviolet rays of 1-390 nm to infrared rays of 750nm -1mm, which are suitable to promote the growth of plants. The principle excitation and emitting spectrum of the red phosphor in 590-700 nm emitting spectrum were in the region of 308nm and 617nm, respectively, whereas, those of the blue phosphor in 420-470nm emitting spectrum were in the region of 254nm and 464nm, respectively. The addition of 0.1-0.2 wt% of the 2:1 mixed red and blue powders to a film showed the maximum emitting intensity of 537x1000 count/sec.