Methodologies have been evolved to grow optical quality nanostructures of the 3.4 eV band-gap semiconductor ZnO and its doped variants with different orders of dimensionality. These nanostructures are versatile and yet under evolution for next generation UV-blue photonic and spin-photonic devices. There are pending lacunae such as reliable and enduring p-type carrier doping and large carrier mobility etc, which need further and deeper understanding of fundamental nature of ZnO as a semiconductor.