AlInN/GaN based multi quantum well structures – growth and optical properties

Abstract

High indium content ([In>]25%) AlInN/GaN multi quantum well structures grown by metal organic vapor phase epitaxy were analyzed by X‐ray diffraction, X‐ray reflection, and photoluminescence measurements. The samples, which exhibit an excellent crystalline quality and smooth interfaces, are found to show broad luminescence below the GaN‐bandgap which shifts with increasing indium content to longer wavelength. At elevated indium content an additional broadening of the luminescence band has been observed. A comparison of the AlInN bandgap and the luminescence energies shows a pronounced stokes shift. XPS measurements reveal a staggered band lineup in Al1‐xInxN /GaN heterostructures with x > 0.25 is found. These findings indicate an indirect transition from the AlInN conduction to the GaN valence band as origin of the luminescence behavior. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Built-in field control in alloyedc-plane III-N quantum dots and wells

“…Since we will be focusing mostly on nearly lattice-and polarizationmatched structures, transitivity holds and the band alignment of the presented InGaN/AlInGaN structures is expected to be Type-I up to at least 25% In in the barrier, following Ref. 50. For InGaN/AlInGaN systems above this limit, and AlGaN/ AlIn(Ga)N systems (which have not been sufficiently studied to date), Type-II transitions cannot be excluded a priori.…”

“…Conventional InGaN/GaN and GaN/ AlGaN systems display Type-I band alignment. 48,49 Hums et al 50 report a transition from Type-I to Type-II alignment in GaN/AlInN systems above 25% In content. Since we will be focusing mostly on nearly lattice-and polarizationmatched structures, transitivity holds and the band alignment of the presented InGaN/AlInGaN structures is expected to be Type-I up to at least 25% In in the barrier, following Ref.…”

Dielectric function and optical properties of Al-rich AlInN alloys pseudomorphically grown on GaN

“…The advantage of these devices is the very high density of the two-dimensional electron gas in the channel layer induced by large spontaneous polarization fields. LM Al 1−x In x N has also a great potential for the application in highly-reflecting distributed Bragg reflectors (DBRs), light-emitting diodes (LEDs), laser diodes (LDs), detectors and sensors [6,7,8,9,10]. Recently, high reflectivity airgap distributed Bragg reflectors were fabricated by wet eching of LM AlInN sacrificial layers [11,12,13] and microdisk (µ-disk) technology, which is used for the new advanced devices, was developed [14].…”

Growth of AlInN/AlGaN distributed Bragg reflectors for high quality microcavities

“…Figure 1 shows the reflectivity and temperature transients during the growth of a 35-pair DBR structure. The temperature needs to be strongly changed for each single layer in order to provide the appropriate growth conditions for the AlInN [13] and AlGaN. The reflectivity remains at a constant mean level during the deposition of the DBR, indicating smooth layers without the appearance of roughening.…”