Semi-polar nitride surfaces and heterostructures
This paper reviews semi-polar nitride surfaces from a theoretical and experimental perspective with regard to light emitting device applications. First, theoretical re-sults on polarization charges at InGaN/GaN heterointer-faces and In incorporation into InGaN films are presented for polar (0001), semi-polar (1122) and non-polar (1100) surfaces. Second, benefits of tuning the electric fields at InGaN/GaN heterointerfaces in sign and magnitude are derived for improving optical and transport properties of quantum well based light emitting devices. This analysis favours semi-polar surfaces such as the (1122) surface for long-wavelength light emitters. Therefore, the ex-perimental part is devoted to progress towards long-wavelength LEDs and lasers by the growth of In-GaN/AlGaN/GaN(1122) heterostructures onto large area GaN(1122)/m-sapphire templates. The current status of such templates as grown by hydride vapour phase epitaxy is presented. The implementation of an epitaxial lateral overgrowth method on such templates to improve device performances is demonstrated.
Strittmatter, A.; Northrup, J. E.; Johnson, N. M.; Kisin, M. V.; El-Ghoroury, H.; Usikov, A.; Syrkin, A. Semi-polar nitride surfaces and heterostructures. Physica Status Solidi (B). 2011 March; 248 (3): 561-573.