Effects Of Junction Temperature And Its Variations On The Performance Of Gan-Based High Power Flip-Chip Leds

In this paper, high power flip-chip GaN-based LEDs were fabricated, and then the effects of junction temperature and its variations were investigated. It was found that the optical output decreases seriously with rising temperature. The variations of junction temperature can be achieved to 9 degrees C at 350 mA in most regions of flip-chip LED except for some hot regions around some electrodes. The combination of screening of quantum confined Stark effect (QCSE) and thermal effect surprisingly makes the peak wavelength constant from 300 mA to 800 mA in electroluminescence spectra. The full-width at half-maximum (FWHM) of emission peak was narrowed by thermal effect in constant current (CC) injection.