Amber-green light-emitting diodes using order-disorder AlxIn1−xP heterostructures

Abstract

We demonstrate amber-green emission from AlxIn1–xP light-emitting diodes (LEDs) with luminescence peaked at 566 nm and 600 nm. The LEDs are metamorphically grown on GaAs substrates via a graded InyGa1–yAs buffer layer and feature electron confinement based on the control of AlxIn1–xP CuPt atomic ordering. A control sample fabricated without order-disorder carrier confinement is used to illustrate device improvement up to a factor of 3 in light output due to confinement at drive currents of 40 A/cm2. The light output at room temperature from our AlxIn1–xP LED structure emitting at 600 nm is 39% as bright as a GaxIn1–xP LED emitting at 650 nm.

Efficient Green Emission from Wurtzite AlxIn1–xP Nanowires

“…Thereby, the positions of the substitutional aluminum and indium ions in the cation sublattice determine the band structure. 44 , 45 We optimize the atomic geometry of the local atomic configurations in 48-atom supercells. The alloy composition is simulated by distributing the Al (In) atoms in four different ways as discussed below.…”

Improved photoluminescence characteristics of order-disorder AlGaInP quantum wells at room and elevated temperatures

“…The (Al x Ga 1Àx ) 0.5 In 0.5 P system exhibits CuPt-B type ordering of Al/Ga and In along the [1][2][3][4][5][6][7][8][9][10][11] or [-111] directions under certain growth conditions. 1 Ordering has been extensively studied in Ga 0.5 In 0.5 P and has been shown to lead to a reduction in band gap, valence band splitting, and an anisotropic matrix element, without a change in macroscopic composition or lattice-constant.…”

“…2 This allows for the opportunity to create lattice-matched order-disorder heterostructures without critical thickness limitations of strained-layer epitaxy. Some potential benefits of using an ordered active layer with disordered barriers include greater carrier confinement, 3,4 increased energy separation from the indirect valley, 5,6 and even bandoffset adjustment. 7 Band-offset adjustment without band gap change is hypothetically possible by compensating for the ordering-induced band gap change with an increased Al/Ga ratio, although this has yet to be experimentally shown.…”

Epitaxy and characterization of AlGaInP-based LEDs on Si substrates for visible-spectrum light emission

“…The luminescence efficiency of a LED sample was estimated by comparing the light output with a reference sample of GaInP red LED on GaAs. The reference sample had very low TDD, good carrier confinement and was free of APBs and thermal strains, so the quantum efficiency was expected to be the highest of GaInP-based LEDs using p-i-n junction [35].…”

“…So far, there is no good solution to provide a strong carrier confinement in AlGaInP yellow-green and green LEDs. By using an ordered/disordered homo-junction LED design and delta-doping to create an internal electrical field, band confinement can possibly be enhanced[35,136].…”