Design and Demonstration of AlxIn1-xP Multiple Quantum Well Light-Emitting Diodes

Direct bandgap Al x In1-x P alloys offer an advantage for red and amber light-emitting diode (LED) operation over conventional (Al x Ga1-x )0.5In0.5P alloys due to their higher direct bandgap energies. However, the coupled variation of its bandgap energy and lattice constant present challenges for fabricating quantum well (QW)-based LED devices on GaAs substrates. Here, we present the design and demonstration of Al x In1-x P red and amber LEDs incorporating multiple QW structures. Strain balancing the QW layers and manipulating the Al x In1-x P conduction band energy through control of spontaneous atomic ordering produce structures with higher energetic barriers to electron leakage compared to (Al x Ga1-x )0.5In0.5P LEDs. We also discuss future improvements that must be made to realize high efficiency red and amber LEDs.