Optimization of Luminescent Features in Multicolor Emitting Rare Earth Doped Alkaline Earth Vanadate Phosphor for Solid State Lighting Applications

Abstract

Recent advances in solid state lighting (SSL) technology have encouraged its utilization newlinein versatile applications. SSL technology based on phosphor converted light emitting diodes newline(pc-LEDs) are acting potentially as a substitute for traditional incandescent and fluorescent newlinelamps on an account of their unprecedented luminous efficiency, low energy consumption, less newlineemission of harmful gases, high brightness, compact design, fast switching and long working newlinelifetimes. The pc-LEDs utilize phosphors coated on the LED chip capable of emitting light in newlinedesirable spectral regions upon an appropriate excitation. In the light of the above mentioned newlineadvantages, pc-LEDs are believed to be the next generation SSL technology and will bring a newlinerevolutionary changes in the lighting industry. For example, the white pc-LEDs have been the newlinemost preferred lighting devices for general illumination due to effective energy utilization, long newlinelifetime, safety and so on. Moreover, pc-LEDs can be harnessed for indoor agricultural lighting newlineowing to their excellence in controlling the spectral composition and lighting intensity to mimic newlinethe changes of sunlight during the day. Therefore, all the above mentioned fascinating features newlinelike effective energy saving and desirable light emission have enabled pc-LEDs to become newlineeconomically feasible choice for general illumination and large scale indoor agricultural newlinelighting applications around the corners of the world. newlineThe phosphor based w-LEDs can be developed by (i) coating of appropriate mixture of newlinered, green and blue (RGB) phosphors excited with UV LED chip (ii) single yellow phosphor newlineby a blue LED chip. However, reabsorption of blue color by RG phosphors in the former newlineapproach and lack of red component in later approach may lead to shortcomings like low color newlinesaturation, deteriorated color rendering index (CRI) and low color temperature stability.