Band discontinuities in zinc-blende and wurtzite AlN/SiC heterostructures
نویسندگان
چکیده
The AlN/SiC band discontinuities in zinc-blende ~110!, ~111!, and wurtzite ~0001! heterostructures were examined using the ab initio pseudopotential approach. At the nonpolar AlN/SiC~110! junction, we find a valence-band offset of 1.7 eV. At the polar heterojunctions the band alignment depends on the interface composition, and valence-band offsets as high as 2.5 eV are obtained for neutral interfaces with an Al/Si mixed plane and as low as 1.3 eV with a N/C mixed plane. Atomic relaxation plays a major role in determining the offset. The structural change from cubic ~111! to hexagonal ~0001! heterojunctions affects predominantly the conduction-band offset, and has only a minor influence on the valence discontinuity. @S0163-1829~97!50612-6#
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