Abstract
The electronic structure of thin-film wurtzite GaN has been studied using a combination of soft-x-ray absorption and emission spectroscopies. We have measured the elementally and orbitally resolved GaN valence and conduction bands by recording Ga and N spectra. We compare the x-ray spectra to the partial density of states from a recent ab initio calculation and find good overall agreement. The x-ray emission spectra confirm that the top of the valence band is dominated by N states whereas they reveal that there is only weak hybridization between Ga and N states. Surprisingly, we found a weak feature in the N emission at approximately 19.5 eV below the valence-band maximum that arises from hybridization between N and Ga states. X-ray absorption spectra show that the bottom of the conduction band is a mixture of Ga and N states, again in very good agreement with the theory.
- Received 27 September 1996
DOI:https://doi.org/10.1103/PhysRevB.54.R17335
©1996 American Physical Society