Epitaxial germanium for photovoltaic or opto-electronic applications

The epitaxial growth of germanium is gaining interest in view of applications in the field of electronic and optoelectronic. By using the epitaxial method more defined doping profiles compared to the diffusion method can be achieved. The problems of doping and doping profiles obtained by epitaxial growth of germanium and the electrical characterization of the photovoltaic devices realized are presented and discussed. Ge rich GeSi/Ge epitaxial grown heterostructures with different Ge profiles are grown by epitaxy on Si substrates to obtain low cost SiGe virtual substrates. High resolution x-ray diffraction and transmission electron microscopy characterizations of this Ge rich layers are presented.