A non-contact method for determining the junction temperature of GaN-based blue light LED

Abstract

A novel method to determine the junction temperature of GaN type blue light LED based on the spectral parameters is proposed. In this method, the relationships among LED junction temperature, centroid wavelength and FWHM are obtained in the lab, and then the junction temperature of operating LED of the same type can be derived from this relationship. A comparative analysis of the junction temperatures which are measured with the centroid wavelength-FWHM method and with the forward voltage method is performed. The standard deviation between these two methods is found to be about 2.3[Formula: see text]C. Therefore, the combination of centroid wavelength and FWHM can be used to determine the junction temperature of GaN-based blue LED.