Nanowires and nanorods made of zincoxide (ZnO) are promising building blocks for future optoelectronic devices operating in the near-UV spectral region. By vapour-phase epitaxy (VPE) nanorods with excellent optical quality and carefully adjustable lengths and diameters can be grown on different substrates. A new low-temperature technique which uses aqueous chemical growth (ACG) for the fabrication of large-scale nanorod arrays provides fascinating possibilities like using flexible plastic substrates. In this project the linear and non-linear optical properties of nanorod ensembles grown by ACG and VPE on different substrates will be systematically analyzed. Emphasis will be put on the possibility of using nanorod samples on transparent substrates as highly efficient non-linear optical devices like frequency doublers. Time-resolved measurements will provide insight into the microscopic processes occurring in ACG nanorods under pulsed optical excitation which up to now have not been addressed in the literature. These experiments should especially explain the role and nature of surface states for the optical properties of this new kind of material. Finally, it will be experimentally analyzed if the growth of nanorods using ACG on metallic layers decreases the lasing threshold in such devices thus allowing for efficient coherent laser emission under optical pumping.
DFG Programme
Priority Programmes
