Investigation of the dual-wavelength light-emitting diodes with AlInGaN spectral adjustment layer based on the Al/In ratios

• We proposed an AlxInyGazN spectral adjustment layer for dual-wavelength LEDs.
• The influences of Al/In ratios for spontaneous emission rate of each MQWs studied.
• The adjustment of emission rate for each MQWs realized with tuning the Al/In ratios.
• We investigated the effects of injection current for emission rate of each MQWs.
• The relation of spontaneous emission rate with injection currents explained.

In this paper, we propose AlxInyGazN quaternary alloys spectral adjustment layer (SAL) for visible spectrum control of dual-wavelength emission in single-chip InGaN/AlInGaN multiple quantum wells (MQWs) light-emitting diodes (LEDs). The mechanism and effects for visible spectrum control with different ratios of Al to In (Al/In) in the AlInGaN spectral adjustment layer are investigated numerically. With the increasing of the Al/In ratios in the spectral adjustment layer, the spontaneous emission rate of In0.08Ga0.92N/Al0.1In0.008Ga0.892N active region increase, while the spontaneous emission rate In0.16Ga0.84N/Al0.1In0.008Ga0.892N active region is suppressed. Besides, the influence of driving current for visible spectrum control is also expounded. The simulation results show that the spontaneous emission rate of In0.16Ga0.84N/Al0.1In0.008Ga0.892N active region could be enhanced more than In0.08Ga0.92N/Al0.1In0.008Ga0.892N active region with the increasing of driving current. By the adjustment of spontaneous rates in the two active regions, the relative luminous spectrum of dual-wavelength in InGaN/AlInGaN LEDs can be controlled.