Preferential Growth of ZnO Micro- and Nanostructure Assemblies on Fs-Laser-Induced Periodic Structures

Abstract

In this work, we demonstrate the use of laser-induced periodic surface structures (LIPSS) as templates for the selective growth of ordered micro- and nanostructures of ZnO. Different types of LIPSS were first produced in Si-(100) substrates including ablative low-frequency spatial (LSF) LIPSS, amorphous-crystalline (a–c) LIPSS, and black silicon structures. These laser-structured substrates were subsequently used for depositing ZnO using the vapor–solid (VS) method in order to analyze the formation of organized ZnO structures. We used scanning electron microscopy and micro-Raman spectroscopy to assess the morphological and structural characteristics of the ZnO micro/nano-assemblies obtained and to identify the characteristics of the laser-structured substrates inducing the preferential deposition of ZnO. The formation of aligned assemblies of micro- and nanocrystals of ZnO was successfully achieved on LSF-LIPSS and a–c LIPSS. These results point toward a feasible route for generating well aligned assemblies of semiconductor micro- and nanostructures of good quality by the VS method on substrates, where the effect of lattice mismatch is reduced by laser-induced local disorder and likely by a small increase of surface roughness.

Quo Vadis LIPSS?—Recent and Future Trends on Laser-Induced Periodic Surface Structures

“… Combined processing strategies: Currently, several research groups are exploring the combination of LIPSS with additional surface treatment techniques—either “in situ” during the laser processing, or “ex situ” after the laser-processing. Examples are: (i) combined laser processing strategies (such as in situ double-pulse treatments [ 20 , 73 , 74 ] or ex situ LIPSS + DLIP, see Section 3.3 ), or a two-step laser processing of microstructures (e.g., lines, grids, or more complex microfluidic channels) patterned additionally with nanostructures (LIPSS) [ 59 , 75 ]; (ii) the combination of LIPSS processing with thermal heat during [ 76 , 77 ] or after [ 78 , 79 ] laser irradiation; (iii) electrochemical post-processing, such as anodization [ 67 , 80 ]; or (iv) ion beam post-processing for altering the electrical conductivity [ 81 ]. Improved regularity of LIPSS through surface overlayers: On dielectrics, the generation of large surface areas covered homogeneously with LIPSS is often very difficult when the single photon energy is significantly smaller than the band gap energy, i.e., when nonlinear absorption is required to couple the laser beam energy with the solid.…”

Characterization of Nb22O54 microrods grown from niobium oxide powders recovered from mine tailings

“…In all cases the temperature was raised to the final value at a rate of 10ºC/min. The microrods obtained have been characterized using several characterization techniques, already described in [22]. First, X-Ray Diffraction measurements (XRD) have been done by means of a PANalytical Empyrean diffractometer using Cu-Kα radiation, with a step in 2θ of 0.05º.…”

Laser-Induced Au Catalyst Generation for Tailored ZnO Nanostructure Growth

“…The substrate is homogeneously covered with similar noble metal catalysts, thus not allowing the growth of different ZnO nanostructure types on a single substrate. In literature, the spatial-selective generation of semiconductor growth is demonstrated, but again only by binary growth control [ 19 , 20 , 25 , 26 ]. To address this limitation we used pulsed laser-induced dewetting (PLiD) of the gold thin films before the thermally induced dewetting and ripening occurring in the ZnO growth process.…”

“…Spatial-selective control of the semiconductor growth is essential for the design of functional devices. The catalyst may be patterned by using a mask [ 18 ], by direct laser writing [ 19 ], or by lithographic methods [ 20 ], leading to binary growth regulation. Nanostructure growth is either fully suppressed or enabled.…”