Study the Surface topography and electrical properties of GaAs:In / c-Si Composite Thin Films

Abstract

Gallium arsenide undoped and doped thin films with 5% Indium and thick of 500 nm by flash evaporative technology on glass substrate and silicon wafers at room temperature at 10-2 mbar pressure with deposition rate of 9.25Å/s. These films were annealed at (373 and 473) K for one hour. The images of the atomic force microscopy of the films deposited on glass substrates showed that the rate of surface roughness increased at the temperature of (373)K while it was reduced at (473)K. It was also observed that the average grain size increased with the increasing in the annealing temperature. The electrical properties showed that the prepared films had an electrical conductivity of 2.05×10-3(Ω.cm)-1and that the annealing led to a decrease in the values of the electrical conductivity while there was an increase in the values of the mobility by increasing the temperature of annealing. A study of Hall's effect showed that all the prepared films have a positive type (p-type) and that the concentration of charge carriers (nH) decreased by increasing the annealing temperature and Hall's mobility (µH) increased by increasing the annealing temperature. The voltage of the open circuit (Voc) increases with the increase in the temperature of the alternation due to the increase of the short circuit current Isc. The value of the FF and the efficiency of the solar cell (η) increases with the increase of the temperature of the intercellular hybrid.