GaAs-Ge non-planar composite epitaxial heterostructures: LPE growth and cathodoluminescence investigations

The composite non-planar GaAs-Ge n-p heterostructures were obtained by liquid phase epitaxy (LPE) of Ge on the porous GaAs[111]B and [100] substrates from Ga-Ge solution. The porous layers were prepared by the anodic electrochemical etching. The capillary effect leads to initial crystallization of Ge in the pores and the formation of the intermixed region between the GaAs substrate and the Ge epilayer. The volume p-n heterostructure was studied by the local cathodoluminescence and scanning electron microscopy. The CL investigation in the IR and visible ranges shows the effective separation of the charge carriers on this volume p-n junction.