Search

We report the epitaxial growth of single-crystalline CdTe(100) thin films on GaAs(100) substrates using molecular beam epitaxy. By controlling the substrate pre-heated temperature with adjustable Te flux, three different reconstructed surfaces are realized, and their influence on the subsequent CdTe growth is investigated. More importantly, we find that both the presence of a thin native oxide layer and the formation of Ga-As-Te bonds at the interface enable the growth along the (100) orientation and help to reduce the threading dislocations and other defects. Our results provide new opportunities for compound semiconductor heterogeneous growth via interfacial engineering.

The differential cross sections for e--Ar and e+-Ar elastic scattering are calculated by relativistic partial wave expansion method. In the processes an incident particle (electron or positron) is treated as moving relativistically in an effective central potential. For electron-atom scattering, the effective potential is calculated by relativistic self-consistent-field (SCF) method with the Slater local exchange approximation. For the positron scattering, the effective potential is the electrostatic potential determined by the ground-state electron charge density calculated by the SCF method. For atomic target polarization due to the incident charge particle(electron or positron), the effect is treated approximately by adding a static polarization potential to the SCF potentials. The calculated results show that the polarization effect is very important for the low energy positron-atom scattering.

Based on theoretical calculations by our non-relativistic configuration interaction computer code, we have successfully identified the x-ray spectra from the cobalt plasma produced by high-power laser. Here we focus on the spectra consisting of x-ray line emission from the N-like and C-like ions. Many new x-ray lines have been identified.