Preparation of nano-structured InGaAs thin film by molecular beam epitaxy

The nano-structured InGaAs films have been prepared by molecular beam epitaxy at different substrate temperature. The substrate temperature was varied from 400degC to 20degC. The samples were characterized by X-ray diffraction and absorption spectra. The results show that the grain size of InGaAs films and the bandgap width increase with increasing substrate temperature. The as-deposited nano-structured InGaAs films have been passivated using hydrogen plasma. The influence of hydrogenation on these InGaAs films has been studied by Fourier transform infrared absorption spectroscopy. These data show the presence of various hydrogen bondings in InGaAs samples prepared at 200degC and 20degC. And the effect of the post hydrogen passivation increases the dark resistivity and photo sensitivity. These results demonstrate the post hydrogen passivation reduces the defects in the films and improves properties of nano-structured InGaAs film.