We report on the current properties of Al1−xInxN (x ≈ 0.18) layers lattice-matched (LM) to GaN and their specific use to realize nearly strain-free structures for photonic and electronic applications. Following a literature survey of the general properties of AlInN layers, structural and optical properties of thin state-of-the-art AlInN layers LM to GaN are described showing that despite improved structural properties these layers are still characterized by a typical background donor concentration of (1–5) × 1018 cm−3 and a large Stokes shift (∼800 meV) between luminescence and absorption edge. The use of these AlInN layers LM to GaN is then exemplified through the properties of GaN/AlInN multiple quantum wells (QWs) suitable for near-infrared intersubband applications. A built-in electric field of 3.64 MV cm−1 solely due to spontaneous polarization is deduced from photoluminescence measurements carried out on strain-free single QW heterostructures, a value in good agreement with that deduced from theoretical calculation. Other potentialities regarding optoelectronics are demonstrated through the successful realization of crack-free highly reflective AlInN/GaN distributed Bragg reflectors (R > 99%) and high quality factor microcavities (Q > 2800) likely to be of high interest for short wavelength vertical light emitting devices and fundamental studies on the strong coupling regime between excitons and cavity photons. In this respect, room temperature (RT) lasing of a LM AlInN/GaN vertical cavity surface emitting laser under optical pumping is reported. A description of the selective lateral oxidation of AlInN layers for current confinement in nitride-based light emitting devices and the selective chemical etching of oxidized AlInN layers is also given. Finally, the characterization of LM AlInN/GaN heterojunctions will reveal the potential of such a system for the fabrication of high electron mobility transistors through the report of a high two-dimensional electron gas sheet carrier density (ns ∼ 2.6 × 1013 cm−2) combined with a RT mobility μe ∼ 1170 cm2 V−1 s−1 and a low sheet resistance, R ∼ 210 Ω/□.

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The authors report a technique for selective wet chemical etching of an AlInN sacrificial layer lattice-matched to GaN for the fabrication of air-gap photonic structures. It is used to demonstrate high quality factor (Q) microdisk cavities. Whispering gallery modes are observed in the photoluminescence spectra of InGaN∕GaN quantum wells (QWs) embedded in the GaN microdisks. Q factors of up to 3500 are obtained. The measured Qs are found to be limited by the QW absorption. Room temperature laser action is achieved for a wide spectral range (409–475nm) with a threshold down to 166kW∕cm2.

The authors report on the achievement of optically pumped III-V nitride blue microdisk lasers operating at room temperature. Controlled wet chemical etching of an AlInN interlayer lattice matched to GaN allows forming inverted cone pedestals. Whispering gallery modes are observed in the photoluminescence spectra of InGaN∕GaN quantum wells embedded in the GaN microdisks. Typical quality factors of several thousands are found (Q>4000). Laser action at ∼420nm is achieved under pulsed excitation at room temperature for a peak power density of 400kW∕cm2. The lasing emission linewidth is down to 0.033nm.

The authors report on the micron scale characterization of a monolithic GaN microcavity (MC) with lattice matched AlInN∕GaN distributed Bragg reflectors by means of a microtransmission setup. This technique allows extracting very high quality factors (Q up to 2800), in accordance with theoretical predictions, contrary to what was previously reported for nitride based MCs. Furthermore, two-dimensional mappings of the MC transmission spectrum allow probing the disorder in this MC. The direct relationship between an increased disorder and a reduction in the Q factor is clearly observed.