Comparative study of structural properties and photoluminescence in InGaN layers with a high In content
Faculty of Sciences. Physics
Warrendale :Materials research society
Internet journal of nitride semiconductor research. - -
Symposium on GaN and Related Alloys Held at the MRS Fall Meeting, NOV 29-DEC 03, 1999, BOSTON, MASSACHUSETTS
, p. art. no.-W11.38
University of Antwerp
Rutherford backscattering and channeling spectrometry (RBS), photoluminescence (PL) spectroscopy and transmission electron microscopy (TEM) have been used to investigate macroscopic and microscopic segregation in MOCVD grown InGaN layers. The PL peak energy and In content (measured by RES) were mapped at a large number of distinct points on the samples. An indium concentration of 40%, the highest measured in this work, corresponds to a PL peak of 710 nn strongly suggesting that the light-emitting regions of the sample me very indium-rich compared to the average measured by RES. Cross-sectional TEM observations show distinctive layering of the InGaN films. The TEM study further reveals that these layers consist of amorphous pyramidal contrast features with sizes of order 10 nm The composition of these specific contrast features is shown to be In-rich compared to the nitride matrix.