Improved tight-binding parameters of III-V semiconductor alloys and their application to type-II superlattices

A simple tight-binding method for ternary semiconductor alloys is generalized to calculate the properties of the semiconductor alloys accurately. Specifically independently adjustable parameters, which represent compositional disorder, are incorporated in all the ternary tight-binding parameters. Energy levels and effective masses agree well with the reference values only by the proposed method. We have applied the method to calculate the band gaps and a spectrum of the absorption coefficient of (InAs)/(GaInSb) type-II superlattices. The calculated band-gaps agree well with the experimental ones and we could well reproduce the shape of the absorption coefficient spectrum calculated by an empirical pseudopotential scheme.

Computer Simulation of the Semiconductor Nanoelectromechanical Systems AIIBIVAs2 Stability after Attosecond Impulse Exposure

The article deals with computer modeling of responses of multicomponent semiconductor nanoelectromechanical systems of arsenides to an attosecond radiation pulse at cryogenic (T1=77 K) and standard temperatures (T2=298 K). Kinetic curves of relaxation processes in ternary semiconductor nanolayers CdSiAs2, CdGeAs2, ZnSiAs2, ZnGeAs2, and nanolayers of variable composition CdSi1-xGex As2, ZnSi1-xGexAs2, Cd1-xZnxSiAs2 и Cd1-xZnxGeAs2 are obtained. This research reveals the differences in the average relaxation energy of nanolayers that depend on temperature and the amplitudes of energy fluctuations, and the time of reaching the plateau. A comparison with relaxation processes taking place at absolute zero temperatures is demonstrated. The radial distribution functions of atoms in the system before and after relaxation processes caused by impulsive action on the system of atoms in the semiconductor layer are considered. The modification of the peaks corresponding to the coordination spheres of atomic distribution depending on the composition of the nanolayer is described. The regularities of relaxation changes of the first order coordination spheres, as well as the regularities of relaxation destructions of the second and the third order coordination spheres at cryogenic and standard temperatures are revealed.