Ground-state energies of shallow states of donor impurities on periodically structured interfaces formed by two semiconductors, such as GaAs/Ga1-xAlxAs and Si/SiO2 interfaces, are calculated variationally with the approximation that interfaces represent infinitely high potential barriers. The results show that the ground-state energies of the interface impurity states can be strongly affected by interface structures in GaAs/Ga1-xAlxAs lateral surface superlattices produced by molecular-beam-epitaxy growth of AlAs/GaAs fractional-layer superlattices on [001] vicinal GaAs substrates and on SiO2/Si interfaces for Si with (001) orientation. The effects of the interface defects on the interface impurity states are negligible for Si/SiO2 interfaces when the density of interface defects is less than 10(10)/cm2.
部门归属
chinese ctr adv sci & technol,world lab,beijing 100080,peoples r china. acad sinica,int ctr mat phys,shenyang 110015,peoples r china.
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