Figure 6From: Controllable synthesis of ZnO nanostructures on the Si substrate by a hydrothermal routePlan-view SEM images of ZnO nanostructures. They are grown (a) without surfactants, (b) with 0.1 ml PEI, and (c) with 2.5 mg of sodium citrate (per 40 ml of reaction solution), at 0.05 M, 80°C for 5 h. (d) PL spectra of ZnO nanostructures in (a), (b), and (c).Back to article page