Abstract
ZnO and GaN have a type-II band offset. The incorporation of one compound into the other would lead to a reduced bandgap as compared to that of either ZnO or GaN. Our density-functional theory calculation reveals an asymmetric bandgap reduction in this nonisovalent system; i.e., incorporating GaN in a ZnO host results in a much more effective bandgap reduction than incorporating ZnO in a GaN host. We further find that the random-alloy system is more favorable than the superlattice system in terms of light absorption in the longer-wavelength regions. Our results suggest that the wave-function localization at the band edges plays an important role in how to choose the host material and dopant for effective bandgap engineering through semiconductor compound alloying.
Original language | American English |
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Article number | 195204 |
Number of pages | 5 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 78 |
Issue number | 19 |
DOIs | |
State | Published - 10 Nov 2008 |
NREL Publication Number
- NREL/JA-520-44865
Keywords
- materials science
- photovoltaics
- semiconductors
- solar energy