Growth modification via indium surfactant for InGaN/GaN green LED

Abstract

In this work, indium (In) was introduced as a surfactant during growth of high temperature GaN quantum barriers (QBs) and GaN interlayer of InGaN/GaN green LEDs. A reference LED grown without In-surfactant was also included for comparison. Results suggested that the LED growth was improved by introducing the In-surfactant, especially during the growth of the GaN interlayer. The In-surfactant improved the morphology of the interlayer, hence allowed it to serve as a good surface growth for the LED. Moreover, the LED showed the lowest full width at half maximum of each x-ray diffraction satellite peak when the In-surfactant was introduced in the GaN interlayer, suggesting an effective way to improve the multi-quantum wells. The introduction of the In-surfactant in the GaN interlayer and GaN QBs growths shifted the emission wavelength of the corresponding LEDs towards red (λ emission = 534 nm) with respect to the reference LED where λ emission = 526 nm. Furthermore, the In-surfactant introduction reduced the forward voltage, V f of the corresponding LEDs down to 4.56 V, compared to the reference LED with V f of 5.33 V. It also allowed the LEDs to show faster carrier decay lifetime, and hence higher radiative recombination, particularly when it was introduced in the GaN interlayer growth.