Comparative Evaluation of the Encapsulating Lens on the Depreciation of the Lumen of High Power Pcleds in Tropical Conditions

Abstract With the current technological growth, the demand for lighting has increased in indoor as well as outdoor application. To meet such huge expectations, Light emitting diodes (LEDs) are inclining towards energy-efficient illumination. However, the useful life of commercially available LEDs is an important parameter. Gradually after passage of time, depreciation in lumen output of LEDs is observed. There are several factors responsible for such degradation in output. One of the reasons is due to bulging of encapsulating lens used on high power pcLEDs. This research discusses the role of encapsulating wafer on LEDs discussing the useful lifetime characteristics of high power pcLEDs. This is an emerging field that combines physics, materials science, device technology and industry. We discuss the effect of lens through systematic observations and calculations are made from the lumen depreciation characteristic graph.