Design of GaN-Based Multicolor Tunnel-Junction Light-Emitting Diodes

The design of monolithic multicolor tunnel-junction (TJ) light-emitting diodes (LEDs) are investigated numerically. This paper primarily aims to design and study monolithic TJ LED devices that possess high luminous efficiency and wide color gamut using a simple fabrication process. First, the characteristics of green and blue single LEDs are explored. Nonuniform carrier distribution inside quantum wells (QWs), which is due to the deep QWs and severe polarization effect, is observed for both single LEDs under study. Based on structural analysis of the single LEDs, streamline dual-color and broadband TJ LED structures, in which the blue unit LED has two pairs of 3-nm-thick QWs and the green unit LED has 3-nm-thick single QW, are designed and investigated. Specifically, monolithic dual-color blue/green (459/530 nm) TJ LED is proposed and analyzed using effective n
⁺
-GaN/i-In
_0.2
Ga
_0.8
N/p
⁺
-GaN TJ. Furthermore, broadband TJ LED with simulated full width at half maximum of around 100 nm is achieved.