Comparative Study of Efficiency Droop in Blue and Red Light-Emitting Diodes Depending on Temperature and Current

Light-emitting diodes (LEDs) have been widely used in many applications such as lighting, display, and automobile as well as medical and agricultural applications. Particularly, for full-color displays using LEDs, the efficiency droop under high temperature or high injection current is one of the important technical issues to be improved. Generally, the efficiency droop is classified into a decrease in efficiency with increasing temperature (T-droop) and with high driving current (J-droop). In blue and red LEDs using different semiconductor materials and structures, the T- and J-droops are expected to be different from each other, but have not yet been systematically investigated. In this study, the causes of the T-droop and J-droop of blue and red LEDs are analyzed by temperature-dependent measurements.Maste