Laser emission of low-threshold excitation from ZnO nanowires

We prepared ZnO nanowires with a controlled reaction in an asymmetrical tube, the nanowire is composed with aligned ZnO QDs packing in the same crystal axis. An anomalous giant oscillator strength was observed in the absorption spectra of the nanowire sol at room temperature. This sol shows stimulated emission at the excitation of a CW He-Cd laser up to an excitation power of more than one hundred.