Zinc oxide nanostructures for hybrid photovoltaics
Undoped and Al-doped planar zinc oxide (ZnO) nucleation layers were used as substrate for catalyst-free ZnO nanostructures grown by pulsed laser deposition (PLD). The low concentration of impurities and the high surface-to-volume ratio makes them suitable for various applications like gas sensors, field-effect transistors and hybrid solar cells.
According to the desired application it is necessary to control the morphology, density and diameter of the nanostructures. Depending on surface polarity of the nucleation layer the morphology changes from small nanorods for O-polar surfaces to a honeycomb-like network of nanowalls for Zn-polar surfaces. The laser fluence governs density and diameter of the nanostructures while the height is determined by the deposition time. Exact control of the parameter of this PLD process enables the fabrication of tailored nanostructures for hybrid photovoltaic devices.
Käbisch et al., Applied Physics Letters 103, 103106 (2013); http://dx.doi.org/10.1063/1.4820410