Epitaxial germanium growth and electrical characterization

Ge homojunctions were deposited by means of Metal Organic Vapour Phase Epitaxy (MOVPE) on Ge substrates at 550 ?C and 675 ?C, using AsH3 as n-type dopant. Gen/Gep, GaAsn/InGaPn/Gen/Gep and Gen/Gep/Gep structures were prepared and studied, where n and p identify the layer or substrate doping. Vertical mesa junctions were obtained on the above structures by using conventional photolithographic and evaporation techniques. The junctions were characterized by I-V measurements under dark and illumination conditions and by EBIC technique. It has been observed that the samples grown at lower temperature showed better rectifying I-V characteristics and light conversion efficiency while EBIC results may suggest that a high As diffusion is present in the samples grown at higher temperature