A semiconductor structure includes a nanocrystalline core comprising a first semiconductor material, and at least one nanocrystalline shell comprising a second, different, semiconductor material that at least partially surrounds the nanocrystalline core. The nanocrystalline core and the nanocrystalline shell(s) form a quantum dot. An insulator layer encapsulates the quantum dot to create a coated quantum dot, and at least one additional insulator layer encapsulates the coated quantum dot.