Research Article
Goud AS and Naranje SM
Abstract
Over the past decades, the common approach to the production of the white Light Emitting Diodes in the lighting industry has been the use of a blue InGaN Light Emitting Diode together with a color correction’ red emitting phosphor and yellow-emitting phosphor Y3Al5O12: Ce3+. However, white Light Emitting Diodes near the Ultra Violet Light Emitting Diode can be combined with the red, green, and blue phosphors. Their combination is due to their improved binging and less the Ultra Violet Light Emitting Diode’s current droop, as well as a better control of the color temperature and color rendering index through the phosphor blends manipulation (Kang 79). The phosphors mentioned above require very high absorption in the range near-Ultra Violet region (Thakur et al. 42). The strong absorption can be obtained from the dipole-allowed 4f and 5d transitions in the rare earth activated ions, such as the Eu2+ and the Ce3+, in a suitable host (Brown and Shand 73). For this approach, the examined phosphors are Ba2MgSi2O7: Eu2+, β-Si AlON-+: Eu2+ and (Sr, Ba) 2SiO4: Eu2+ for the green emitting component, CaAlSiN3: Ce3+ and Sr3Si05: Eu2+ for the orange/ yellow-emitting component, and (Sr, Ca) 2 Si5N8: Eu2+ for the red-emitting component.