Emission Mechanism of Light-Emitting Diode Structures with Red, Green, and Blue Active Layers Separated by Si-Doped Interlayers

Blue, green, and red micro-light-emitting diodes (LEDs) are expected to serve as light sources for next-generation full-color displays. This study fabricates an InGaN LED with an active layer comprising stacked red, green, and blue active layers separated by interlayers using the metal-organic vapor-phase epitaxy method for application to a monolithic full-color LED. Experimental results and band simulations reveal that the emission wavelength during the current injection is controllable via adjustments to the Si doping amount of the interlayer. For a Si doping amount of the interlayer of approximately 2 x 10(18) cm(-3), only the red active layer closest to the p-side emits light with a wavelength of & AP;610 nm. With a decrease in the Si doping amount in the interlayer, the emission intensity from the n-side active layer, that is, the green and blue active layers, increases. Moreover, the Si-doped interlayer acts as a barrier against holes diffusing from the p-side to the n-side, thus controlling the amount of carrier injected into each active layer. Additionally, the green and blue active layers under the red active layer improve the emission characteristics of the red active layer. These results indicate the importance of this technology for realizing monolithic, full-color InGaN-based LEDs.