单层超晶格Ga_(0.47)In_(0.53)As/InP(110)及半导体合金Ga_(0.235)In_(0.765)P_(0.5)As_(0.5)的状态密度及介电常数(英文)

The Densities of State and Dielectric Constants of Monolayer Superlattice Ga_(0.47)ln_(0.53)As/lnP(110) and Alloy Ga_(0.235) In_(0.765)P_(0.5)As_(0.5)

The DOS, JDOS and ε2(Ω) of monolayer superlattice Ga0.47ln0.53As/ InP(110) have been calculated by a tight-binding approach and compared with that of alloy Ga0.235ln0.765P0.5As0.5 which has the same stoi-chiometric composition as the monolayer superlattice. By using the techniques of the group theory we have obtained the expressions of momentum matrix elements between valence band states and conduction band states with four adjustable parameters. These parameters are determined by fitting the calculated values of ε2(Ω) with the experimental values for InP, GaAs and InAs. Our results show that the superlattice periodicity makes its DOS, JDOS and ε2(Ω) different from those of alloy in varying degree. Due to the folding of Brillouin zone, the JDOS of superlattice turns round in comparison with that of alloy. The momentum matrix elements have different effects for the superlattices and alloys.For the alloys, they can only change the amplitudes of peaks but not the positions of peaks; however, for the superlattices both amplitude and position can be changed.