Luminescence properties of InGaN‐based dual‐wavelength light‐emitting diodes with different quantum‐well arrangements

Abstract

Optimized dual-wavelength InGaN-based vertical light-emitting diode (LEDs) structures were investigated by numerical simulations. The results show that different quantum-well arrangements in the active region play an important role in obtaining dual-wavelength emission. It is a better way to obtain the dual-wavelength with uniform intensity by arranging quantum wells (QW) with low indium content near the p-side and the QW with high indium near the n-side. This is because the QWs with lower indium near the p-side layer have higher hole-injection efficiency. On the other hand, arranging QW with high indium content near the p-side leads to poor holeinjection efficiency due to the high polarization fields. The physical and optical mechanisms of these phenomena were explained by the intensity of electrostatic fields, energy-band diagrams, and carrier-concentration distribution in the active region of LEDs.

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

“…[ 22,36,37 ] The fact that the intensity of red emission in samples Y1 and Z1 was higher than that in sample X indicates that this structure offered the same advantages; and 2) The number of holes injected into each active layer could be easily controlled via simple adjustments to the Si concentration in the interlayers; moreover, only the p‐side active layer could be made to emit light. [ 44–48 ]…”

“…[22,36,37] The fact that the intensity of red emission in samples Y1 and Z1 was higher than that in sample X indicates that this structure offered the same advantages; and 2) The number of holes injected into each active layer could be easily controlled via simple adjustments to the Si concentration in the interlayers; moreover, only the p-side active layer could be made to emit light. [44][45][46][47][48] The realization of the following light-emitting devices can be expected by utilizing these technical advantages. The first was a single-die white LED that did not use phosphor.…”

Monolithic active-matrix full-color micro-LED micro-display using InGaN/AlGaInP heterogeneous integration

“…But the difference is the relative emission intensity of blue and green light in dual-wavelength epiwafers can be adjusted by applying different current densities or adopting different configurations of blue and green QWs. Research of blue/green dual-color LED devices on the sapphire substrate [27][28][29] has been reported in the past. The fabrication process of the blue/green dual-color GaN-on-Si micro-LED display is similar to our previous report of high-resolution and high-brightness GaN-on-Si blue monochromatic display [30].…”

Quantum Efficiency Enhancement of a GaN-Based Green Light-Emitting Diode by a Graded Indium Composition p-Type InGaN Layer

“…Here, the band-offset ratio between the conduction band and the valence band for InGaN/GaN MQWs was 70% [ 40 ]. In addition, the values of the Shockley-Read-Hall (SRH) recombination lifetime and Auger coefficients assumed in this simulation were 50 ns and 1 × 10 −30 cm 6 /s, respectively [ 41 , 42 , 43 ]. Figure 3 c displays the calculated EL spectra at 300 mA, which shows a similar trend of enhancement in light intensity with measured results.…”