Abstract
GaN thin films were grown by molecular beam epitaxy on sapphire substrates. Scanning electron (SE) and atomic force microscopies reveal that on a typical film an assembly of oriented hexagonal microcrystallites rises above a background of polycrystalline or amorphous material. Cathodoluminescence (CL) spectra of the films feature bright UV exciton peaks and a broad green emission band. We identify the exciton peaks as those of the wurtzite form of GaN. A comparison of SE and CL micrographs of the same sample area shows that the luminescence emanates almost entirely from the hexagonal crystallites.
Original language | English |
---|---|
Pages (from-to) | 355-357 |
Number of pages | 3 |
Journal | Applied Physics Letters |
Volume | 68 |
Issue number | 3 |
DOIs | |
Publication status | Published - 1 Dec 1996 |
Keywords
- luminescence
- GaN films
- sapphire substrates