Energy loss of H+ and He+ in the semiconductors GaAs, ZnSe, InP and SiC

We have theoretically studied the electronic stopping cross section and the energy loss straggling of swift light ions (H+ and He+) moving through several compound semiconductors (GaAs, ZnSe, InP and SiC) as a function of the incident projectile energy. The calculations have been done using the dielectric formalism, in which the electronic structure of the projectile is described by the modified Brandt-Kitagawa model and the energy loss function (ELF) of the semiconductors is obtained using a linear combination of Mermin-type ELF to describe the outer electron excitations and generalized oscillator strengths to take into account the excitations of the inner-shell electrons. The different charge states that the projectile can acquire during its travel through the solid, as a result of electronic capture and loss processes, has been also considered. The contributions to the projectile energy loss from both the outer- and the inner-shell electron excitations are analyzed. The comparison of our calculated stopping cross sections with available experimental data shows a good agreement in a wide range of incident projectile energies.