Growth of aligned arrays of ZnO nanorods by low temperature solution method on Si surface

Abstract

We report growth of ZnO nanorods by low temperature (<100°C) solution growth method. The substrates (Si, glass and fused Quartz) were seeded by pre-coating with ZnO nanoparticles (4–7 nm diameter) prepared by chemical precipitation route. Nanorods were grown on the seeded substrate in aqueous solution of Zinc Nitrate and Hexamethylenetetramine (HMT). The growth process lasts for up to 8 h and at the maximum time of growth, the nanorods have a width of ∼230–250 nm and length of ∼1.5–1.6 μm. The growth process after some initial growth (<2 h) preserves the aspect ratio and leads to about 90% texturing along the (002) direction. The growth of the nanorods was studied with time and observed growth data suggests a two-stage growth process. The nanorods have a well-defined hexagonal morphology and have a Wurtzite structure. The nanorods were characterized by different techniques and have a band gap of 3.25 eV.