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

Abstract

Direct bandgap Al x In 1−x P alloys offer an advantage for red and amber light-emitting diode (LED) operation over conventional (Al x Ga 1−x ) 0.5 In 0.5 P 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 In 1−x P red and amber LEDs incorporating multiple QW structures. Strain balancing the QW layers and manipulating the Al x In 1−x P conduction band energy through control of spontaneous atomic ordering produce structures with higher energetic barriers to electron leakage compared to (Al x Ga 1−x ) 0.5 In 0.5 P LEDs. We also discuss future improvements that must be made to realize high efficiency red and amber LEDs.

Inhomogeneous Barrier Height Characteristics of n-Type AlInP for Red AlGaInP-Based Light-Emitting Diodes

“…In this regard, a conventionally used n-GaAs capping layer was replaced by an n-AlInP confinement layer because the former has smaller energy bandgap (1.44 eV) than direct bandgap Al x In 1-x P layers (x > 0.35) (2.07-2.19 eV) and so mostly absorbs red light emitted from the active region, reducing light extraction. 10,11 Furthermore, AlInP layers have been utilized as active, confinement, and passivation layers in various optoelectronic devices, including heterojunction bipolar transistors, 12 field-effect transistor 13 and solar cells. 14 For these applications, the high-performance Schottky and Ohmic contacts is a substantially important process.…”