Soft Solution Route to Directionally Grown ZnO Nanorod Arrays on Si Wafer; Room‐Temperature Ultraviolet Laser

Abstract

A high‐quality ZnO nanorod array (NRA) has been successfully grown on a Si wafer by a wet‐chemical process, where the Si wafer was dip‐coated with 4 nm sized ZnO nanoparticles as a buffer and seed layer prior to the crystal growth. It is found that the as‐prepared ZnO NRA has a threshold power density of ∼ 70 kW cm–2, which is comparable to the lowest one determined for ZnO NRAs on Al2O3 substrates (40 kW cm–2). The ultraviolet lasing efficiency of the ZnO NRAs is thus similar for both substrates.