On spectral and thermal behaviors of AlGaInP light-emitting diodes under pulse-width modulation

Abstract

Behavior of the emission spectrum, junction temperature, and charge carrier temperature of low-power AlGaInP light-emitting diodes (LEDs) with different colors under pulse-width-modulation (PWM) dimming is investigated. The blueshift of the peak wavelength and the bandwidth narrowing in the emission spectra of the studied LEDs with shortening pulse are found. A linear relation of the junction temperature and carrier temperature of the studied LEDs to their duty cycle is detected. Perceivable changes in color of AlGaInP LEDs under the PWM scheme are observed.