High concentrations of defects are introduced into nanoscale ZnO through non‐equilibrium processes and resultant blue emissions are comprehensively analyzed, focusing on defect origins and broad controls. Some ZnO nanoparticles exhibit very strong blue emissions, the intensity of which first increase and then decrease with annealing. These visible emissions exhibit strong and interesting excitation dependences: 1) the optimal excitation energy for blue emissions is near the bandgap energy, but the effective excitation can obviously be lower, even 420 nm (2.95 eV < Eg = 3.26 eV); in contrast, green emissions can be excited only by energies larger than the bandgap energy; and, 2) there are several fixed emitting wavelengths at 415, 440, 455 and 488 nm in the blue wave band, which exhibit considerable stability in different excitation and annealing conditions. Mechanisms for blue emissions from ZnO are proposed with interstitial‐zinc‐related defect levels as initial states. EPR spectra reveal the predominance of interstitial zinc in as‐prepared samples, and the evolutions of coexisting interstitial zinc and oxygen vacancies with annealing. Furthermore, good controllability of visible emissions is achieved, including the co‐emission of blue and green emissions and peak adjustment from blue to yellow.

Besides the traditional lithographical techniques to fabricate the ordered mciro/nanostructured arrays, the route of the monolayer colloidal crystal template is a recently promising, alternative process for the synthesis of the micro/nanostructures with different designed morphologies. By this strategy, twodimensional ordered arrays, e.g., nanoparticle arrays, pore arrays, nanoring arrays, nanobowl arrays, hollow sphere arrays, etc., even one-dimensional nanostructures of ordered nanorod/nanopillar/nanowire arrays, etc., could be prepared. Recent progress in this area is reviewed, including synthesis strategies and morphology-dependent properties of the micro/nanostructured arrays such as optical properties, wettability, surface-enhanced Raman scattering, and photonic bandgap.