Role of strain in polarization switching in semipolar InGaN/GaN quantum wells

Effects of strain on the band structure of group-III nitrides

We present a systematic study of strain effects on the electronic band structure of the group-IIInitrides (AlN, GaN and InN). The calculations are based on density functional theory (DFT) with band-gap-corrected approaches including hybrid functional and quasiparticle G0W0 methods. We study strain effects under realistic strain conditions, hydrostatic pressure and biaxial stress. The strain-ind...

MOVPE Growth of Semipolar GaN on Patterned Sapphire Wafers: Growth Optimisation and InGaN Quantum Wells

We are able to achieve two different GaN semipolar surfaces by growing on patterned sapphire substrates: (101̄1) GaN on (112̄3) sapphire and (112̄2) on (101̄2). By this approach, the growth of a coalesced semipolar layer on a large area of about two inches diameter is possible. Well known from the c-plane direction, an in-situ deposited SiN interlayer could reduce the defect density also in semipol...

Fabrication and optical properties of nano-structured semipolar InGaN/GaN quantum wells on c-plane GaN template

Band Structure Measurements and Calculations of Epitaxially Grown GaN Based Photonic Crystal Slabs with Semipolar Quantum Wells

We report on the large area realization of GaN photonic crystal slabs with semipolar InGaN quantum wells (QWs) using laser interference lithography and selective area metalorganic vapour phase epitaxy (MOVPE). Directional extraction of guided modes was observed in angle-resolved photoluminescence spectroscopy (ARPL), and the photonic crystal slab dispersion relation was measured. A comparison o...

HVPE Growth on MOVPE-Grown Semipolar (112̄2) GaN 75 HVPE Growth on MOVPE-Grown Semipolar (112̄2) GaN

For the GaN material system, one reason for the breaking down of the efficiency is the socalled quantum confined Stark effect (QCSE). Since today’s LEDs are grown in the common [0001] (c-)direction, the internal polarization fields are perpendicular to the quantum wells. The cause of these internal fields are spontaneous and piezoelectric polarization. The reason for the latter is mechanical st...