The photoluminescence of the diverse nanostructures of nonstoichiometric ZnO grown via carbothermal reduction at 900°C was investigated. Various formations of different structures like wires, rods, tubes and tetrapods resulted from the inhomogeneity of the boundary diffusion layer associated with vapor current induced in the set-up. The band gap emission of these structures was observed at around 390 nm, which corresponds to energy of 3.20 eV. The study was extended to measure changes of crystal habit of ZnO nanostructures in terms of its fractal dimension.