Determination of Efficiency of Light-Emitting Diodes Using Energy Conservation

The efficiency of light-emitting diodes is studied using energy conservation. Efficiency is an important parameter for light-emitting diodes. However, efficiency of light-emitting diodes involves complicated phenomena of light, electricity and heat. It is difficult for efficiency to model in mathematical form theoretical formula. ABC model is usually used as a standard mathematical form, but it is more suitable for explanation of efficiency droop. This work proposes a theoretical model to predict efficiency of light-emitting diodes. The energy conservation among input power, light-output power, and dissipation heat power is employed to determining the efficiency. It is revealed that the efficiency of the AlGaInP LED hardly decreases with the increasing forward current. The possible reason is low series resistance of AlGaInP LED. Effects of material poperties on the efficiency AlGaInP LED is discussed. Keywords - Light-emitting diodes, Forward current, Junction temperature, Light power.