Multi Bandgap Photodetectors with Buried Epitaxial Metallic Contacts.

摘要

A method for growing single crystal arrays of semimetallic vertical and horizontal erbium antimonide nanorods, nanotrees, and nanosheets embedded within a semiconducting gallium antimonide matrix was investigated. The nanostructures form simultaneously with the matrix and have epitaxial, coherent interfaces with no evidence of stacking faults or dislocations as observed by high-resolution transmission electron microscopy. By combining molecular beam epitaxy growth and in-situ scanning tunneling microscopy, images of the growth surface one atomic layer at a time showed that the nanostructured composites form via a surface mediated self-assembly mechanism that is controlled entirely at the growth front and is not a product of bulk diffusion or bulk segregation. These highly tuneable nanocomposites show promise for direct integration into epitaxial semiconductor device structures, and also provide a unique system in which to study the atomic scale mechanisms for nucleation and growth.