Skip to Main Content
Your organization might have access to this article on the publisher's site. To check, click on this link:http://dx.doi.org/+10.1063/1.125289
The microscopic spectral emission characteristic of an InGaN/GaN double-heterostructure light-emitting diode is directly imaged by highly spectrally and spatially resolved scanning electroluminescence microscopy under operation as a function of injection current density. The luminescence intensity maps and especially the peak-wavelength scanning images provide access to the optical quality of the final device and yield direct images of the In fluctuations with 1 μm spatial resolution. Indium concentrations varying from 6% to 9% are found in the active InGaN region of the ultraviolet diode emitting at 400 nm. While for low injection current densities the electroluminescence is dominated by emission from the p GaN originating from the whole accessible area, the emission from the InGaN active layer increases and takes over for higher injection conditions showing a strongly localized spatial emission characteristic. Correlation of the results with low-temperature scanning photoluminescence microscopy enables the identification of the underlying recombination processes. © 1999 American Institute of Physics.