Confocal spectroscopy of InGaN LED structures

D Dobrovolskas, J Mickevičius, E Kuokštis, G Tamulaitis, M Shur, M Shatalov, J Yang, R Gaska
2011 Journal of Physics D: Applied Physics  
Photoluminescence of InGaN structures for green light emitting diodes with multiple quantum wells as an active medium was studied with spatial and spectral resolution using confocal microscopy. Bright spots of~200 nm in diameter were observed. Emission from these bright areas was up to 8 times more intense than from the rest of the sample surface and the band peak position in these areas was blueshifted in respect to the band position in the background surface of lower photoluminescence
more » ... uminescence intensity. The data on emission properties in bright and dark areas and the dependence of these properties on the excitation power density are interpreted by assuming inhomogeneous distribution of defects acting as nonradiative recombination centers.
doi:10.1088/0022-3727/44/13/135104 fatcat:jfh6pi7ne5gobab3ephn6rzh2m