YAG:Ce³⁺, Gd³⁺nano-phosphor for white light emitting diodes

YAG:Ce3+, Gd3+ nano-phosphors were synthesised by the glycothermal method. The X-ray diffraction measurements showed that the samples can be well-crystallised at 600°C. The transition electron microscope showed that the particles have sizes mostly in the range between 35 and 100 nm. The YAG:Ce nano-phosphor had a wide emission band ranging from blue to yellow with a peak at 532 nm, due to the transition from the lowest 5d band to 2F7/2, 2F5/2 states of the Ce3+ ion. Red-shift of emission peak wavelength from 532 to 568 nm was achieved doping Gd3+ ions into the YAG:Ce3+ to substitute some Y3+ ions. White light emitting diodes (LEDs) were obtained by combining blue LED chip (InGaN-based 460 nm emitting) with (Y2.94− x Ce0.06Gd x )Al5O12 phosphor. As x has the value of 0.8, an intense white LED with good colour rendering of 86 was obtained.