Advanced characterization techniques of nonuniform indium distribution within InGaN/GaN heterostructures grown by MOCVD

• Published in: Physica status solidi. A, Applications and materials science Applications and materials science, 2005-04, Vol.202 (5), p.795-798
• Main Authors: Lu, D., Florescu, D. I., Lee, D. S., Ramer, J. C., Parekh, A., Merai, V., Li, S., Gardner, J. J., Begarney, M. J., Armour, E. A.
• Format: Article
• Language: English
• Subjects: 68.37.Hk; 68.37.Ps; 68.55.Nq; 78.55.Cr; 81.05.Ea; 81.15.Gh; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Physics
• ISSN: 1862-6300; 0031-8965; 1862-6319; 1521-396X
• DOI: 10.1002/pssa.200461503

Nonuniform indium distribution within InGaN/GaN single quantum well (SQW) structures with nanoscale islands grown by metalorganic chemical vapor deposition (MOCVD) have been characterized by advanced characterization techniques. Robinson backscattered electron (BSE) measurements show cluster‐like BSE contrast of high brightness regions, which are not centered at small dark pits in a SQW structure of spiral growth mode. By comparing with the secondary electron (SE) images, the bright cluster areas from the BSE images were found to have higher indium content compared to the surrounding dark areas. Temperature dependant photoluminescence (PL) measurement shows typical “S‐shape” curve, which shows good correlation with nonuniform indium distribution from BSE measurement. Optical evaluation of the samples show increased PL slope efficiency of the spiral mode SQW, which can be attributed to the presence of Indium inhomogeneities. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)