Enhanced photoluminescence from InGaN/GaN quantum wells on a GaN/Si(111) template with extended three-dimensional GaN growth on low-temperature AIN interlayer

This paper describes a low-cost route for the reduction of dislocations during growth of GaN on Si(111) using metalorganic vapour phase epitaxy (MOVPE) through three-dimensional (3D) island growth on a low temperature AlN layer which introduces a compressive stress into the over-lying GaN layer to compensate for the thermal mismatch stress between the nitride layer and Si(111) substrate. Such a 3D growth process leads to the reduction of grain twist as the result of the reduction in the number of dislocations having a component parallel to the basal plane. The dislocation reduction process leads to a more uniform luminescence from InGaN/GaN quantum wells, as revealed by spectrally-resolved cathodoluminescence imaging of the cross-section of samples.