Dynamic Response-Based LEDs Health and Temperature Monitoring

Abstract This paper presents a number of novel methods to measure the junction temperature and to estimate the health of gallium nitride light-emitting diodes (LEDs). The methods are based on measurements of the dynamic impedance and optical output. Our experimental analysis reveals temperature sensitive parameters of the electrical and optical responses. Moreover, a correlation between the non–radiative current characterizing the defects in the active region and the small-signal impedance is demonstrated. The demonstrated methods can be applied to enhance existing temperature-monitoring techniques. The derived dependencies also build a foundation for advanced in–field monitoring health of the LEDs and for prediction of imminent failures using the infrastructure of visible light communication systems. Such models are valuable for predictive maintenance.