Semiconductor structures having a nanocrystalline core and corresponding nanocrystalline shell and insulator coating are described. In an example, a semiconductor structure includes an anisotropic nanocrystalline core composed of a first semiconductor material and having an aspect ratio between, but not including, 1.0 and 2.0. The semiconductor structure also includes a nanocrystalline shell composed of a second, different, semiconductor material at least partially surrounding the anisotropic nanocrystalline core. An insulator layer encapsulates the nanocrystalline shell and anisotropic nanocrystalline core.